Optical sensor

ABSTRACT

The present disclosure relates to an optical sensor module, an optical sensing accessory, and an optical sensing device. An optical sensor module comprises a light source, a photodetector, and a substrate. The light source is configured to convert electric power into radiant energy and emit light to an object surface. The photodetector is configured to receive the light from an object surface and convert radiant energy into electrical current or voltage. An optical sensing accessory and an optical sensing device comprise the optical sensor module and other electronic modules to have further applications.

FIELD

The disclosure relates generally to optical sensors and associatedapplications to collect and manage the signals.

BACKGROUND

The reflective optical sensor module emits light and measures the amountof reflected light from an object. The optical sensor module convertselectrical current into light, which is directed onto the surface of anobject, and converts the reflected light into electrical signals. Theincident light can then be reflected by the object, absorbed by theobject, or scattered by the object. A portion of reflected and scatteredlight can reach a photodetector of the optical sensor module; thereceived reflected and scattered light produces a corresponding signal.The corresponding signal portion is described as “the signal portion”when calculating a signal to noise ratio (SNR). The signal portion maybe attenuated due to a loss of a portion of emitted light, which iseither absorbed by the object or escaping from being detected by aphotodetector. The noise portion mainly comes from the emitted lightdirectly detected by a photodetector and ambient light detected by thephotodetector. Due to the poor light guide efficiency, both incidentlight leakage and stray light disturbance decrease the SNR, andtherefore lead to inaccuracy of the optical sensor module.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of the present technology will now be described, by wayof example only, with reference to the attached figures.

FIGS. 1A and 1B are schematic diagrams of a cross-sectional view of anoptical sensor in accordance with a first and a second embodiments ofthe present disclosure.

FIG. 2A-2C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor inaccordance with an embodiment of the present disclosure.

FIG. 3A-3C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor inaccordance with an embodiment of the present disclosure.

FIG. 4A-4C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor inaccordance with an embodiment of the present disclosure.

FIG. 5A-5C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor inaccordance with an embodiment of the present disclosure.

FIG. 6A-6C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor with anobject surface in accordance with an embodiment of the presentdisclosure.

FIG. 7A-7C are schematic diagrams of an optical sensor module comprisinga cover applied on an object surface.

FIG. 8A is a cross-sectional view of an optical sensor module comprisinga cover applied on an object surface; FIG. 8B is a partial enlarged viewof the double-sided thin film cover.

FIG. 9A is a cross-sectional view of the thin film coated encapsulants;FIG. 9B is a partial enlarged view of the first thin film coatedencapsulant; FIG. 9C is a partial enlarged view of the second thin filmcoated encapsulant.

FIG. 10A is a cross-sectional view of the optical sensor modulecomprising a cover and the thin film coated encapsulants; FIG. 10B is apartial enlarged view of the first thin film coated encapsulant; FIG.10C is a partial enlarged view of the second thin film coatedencapsulant.

FIG. 11A is a cross-sectional view of the optical sensor modulecomprising a double-sided thin film cover and the thin film coatedencapsulants; FIG. 11B is a partial enlarged view of the double-sidedthin film cover, FIG. 11C is a partial enlarged view of the first thinfilm coated encapsulant, and FIG. 11D is a partial enlarged view of thesecond thin film coated encapsulant.

FIG. 12A-12C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with one embodiment of the present disclosure.

FIG. 13A-13C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 14A-14C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 15A-15C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 16A is a schematic diagram of a cross-sectional view of an opticalsensor in accordance with one embodiment of the present disclosure; FIG.16B is the schematic diagram of a cross-sectional view of one of theencapsulants. FIG. 16C-16E are the graphs of the refractive index as afunction of the distance from the substrate, wherein the horizontal axisrepresents the distance and the vertical axis represents the refractiveindex.

FIG. 17A-17C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 18A-18C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 19A-19C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 20A-20C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 21A-21C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 22A-22C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 23A-23C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 24A-24C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 25A-25C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 26A-26C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 27A-27C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 28A-28C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 29A-29C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 30A-30C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 31A-31C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 32A-32C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 33A-33C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 34A-34C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 35A-35C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 36A-36C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 37A-37C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 38A-38C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 39A is a cross-sectional view of the optical sensor modulecomprising a double-sided thin film cover and the thin film coatedencapsulants applied on an object surface; FIG. 39B is a partialenlarged view of the double-sided thin film cover.

FIG. 40A is a cross-sectional view of the optical sensor modulecomprising the thin film coated encapsulants applied on an objectsurface; FIG. 40B is a partial enlarged view of the first thin filmcoated encapsulant; FIG. 40C is a partial enlarged view of the secondthin film coated encapsulant.

FIG. 41A is a cross-sectional view of the optical sensor modulecomprising a double-sided thin film cover and the thin film coatedencapsulants applied on an object surface; FIG. 41B is a partialenlarged view of the first thin film coated encapsulant; FIG. 41C is apartial enlarged view of the second thin film coated encapsulant.

FIG. 42A is a cross-sectional view of the optical sensor modulecomprising a double-sided thin film cover and the thin film coatedencapsulants applied on an object surface; FIG. 42B is a partialenlarged view of the double-sided thin film cover; FIG. 42C is a partialenlarged view of the first thin film coated encapsulant; FIG. 42D is apartial enlarged view of the second thin film coated encapsulant.

FIG. 43A-43C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 44A-44C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 45A-45C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 46A-46B are schematic diagrams of a top view and cross-sectionalview of an optical sensor module in accordance with an embodiment of thepresent disclosure.

FIG. 47A-47B are schematic diagrams of a top view and cross-sectionalview of an optical sensor module applied to an object surface inaccordance with an embodiment of the present disclosure.

FIG. 48A-48B are schematic diagrams of a top view and cross-sectionalview of an optical sensor module comprising a cover applied to an objectsurface in accordance with an embodiment of the present disclosure.

FIG. 49A-49C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor modulecomprising a cover in accordance with an embodiment of the presentdisclosure.

FIG. 50A-50C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor modulecomprising a cover in accordance with an embodiment of the presentdisclosure.

FIG. 51A-51C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor modulecomprising a cover in accordance with an embodiment of the presentdisclosure.

FIG. 52A-52C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor modulecomprising a cover in accordance with an embodiment of the presentdisclosure.

FIG. 53A-53C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor modulecomprising a cover in accordance with an embodiment of the presentdisclosure.

FIG. 54A-54C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor modulecomprising a cover in accordance with an embodiment of the presentdisclosure.

FIG. 55A-55C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor modulecomprising an analogue front end in accordance with an embodiment of thepresent disclosure.

FIG. 56A-56B are schematic diagrams of a top view and oblique view,respectively, of an optical sensor module comprising an analogue frontend in accordance with an embodiment of the present disclosure.

FIG. 57A-57B are schematic diagrams of a top view and oblique view,respectively, of an optical sensor module comprising an analogue frontend and a microcontroller in accordance with an embodiment of thepresent disclosure.

FIG. 58A-58B are schematic diagrams of a top view and oblique view,respectively, of an optical sensor module comprising an analogue frontend and a microcontroller in accordance with an embodiment of thepresent disclosure.

FIG. 59A-59B are schematic diagrams of a top view and oblique view,respectively, of an optical sensor module comprising a plurality ofanalogue front end and a microcontroller in accordance with anembodiment of the present disclosure.

FIG. 60A-60B are schematic diagrams of a top view and oblique view,respectively, of an optical sensor module comprising an operationalamplifier, a light source driver and a microcontroller in accordancewith an embodiment of the present disclosure.

FIG. 61A-61C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 62A-62C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensing modulein accordance with an embodiment of the present disclosure. FIG. 62D isthe side view of an optical sensor module from the side of contactsurface.

FIG. 63A-63C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensing modulein accordance with an embodiment of the present disclosure. FIG. 63D isthe side view of an optical sensor module from the side of contactsurface.

FIG. 64A-64C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 65A-65C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensing modulein accordance with an embodiment of the present disclosure. FIG. 65D isthe side view of an optical sensor module from the side of contactsurface.

FIG. 66A-66C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 67A-67C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 68A-68C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensing modulein accordance with an embodiment of the present disclosure. FIG. 68D isthe side view of an optical sensor module from the side of contactsurface.

FIG. 69A-69C are schematic diagrams of a top view, cross-sectional view,and oblique sectional view, respectively, of an optical sensor module inaccordance with an embodiment of the present disclosure.

FIG. 70A-70B are schematic diagrams of a top view and cross-sectionalview, respectively, of an optical sensor module in accordance with anembodiment of the present disclosure.

FIG. 71A-71B are schematic diagrams of a top view and cross-sectionalview, respectively, of an optical sensor module in accordance with anembodiment of the present disclosure.

FIG. 72A-72B are schematic diagrams of a top view and cross-sectionalview, respectively, of an optical sensor module in accordance with anembodiment of the present disclosure.

FIG. 73A-73B are schematic diagrams of a top view and cross-sectionalview, respectively, of an optical sensor module in accordance with anembodiment of the present disclosure.

FIG. 74A-74B are schematic diagrams of a top view and cross-sectionalview, respectively, of an optical sensor module in accordance with anembodiment of the present disclosure.

FIG. 75A-75B are schematic diagrams of a top view and cross-sectionalview, respectively, of an optical sensor module comprising a cover inaccordance with an embodiment of the present disclosure.

FIG. 76A-76B are schematic diagrams of a top view and cross-sectionalview, respectively, of an optical sensor module comprising a cover inaccordance with an embodiment of the present disclosure.

FIG. 77A-77B are schematic diagrams of a top view and cross-sectionalview, respectively, of an optical sensor module comprising a cover inaccordance with an embodiment of the present disclosure.

FIG. 78A is a cross-sectional view of the optical sensor modulecomprising a double-sided thin film cover; FIG. 78B is a partialenlarged view of the double-sided thin film cover.

FIG. 79A is a cross-sectional view of the optical sensor modulecomprising a cover and the thin film coated encapsulants; FIG. 79B is apartial enlarged view of the first thin film coated encapsulant; FIG.79C is a partial enlarged view of the second thin film coatedencapsulant.

FIG. 80A-80D are schematic diagrams of the housing of an optical sensingaccessory or an optical sensing device. FIG. 80A is an example of thehousing for a handheld device. FIGS. 80B and 80 C is an example of theannular shape housing for a wearable device. FIG. 80D is an example ofthe patch shape housing for a wearable device.

FIG. 81A is a block diagram of an optical sensing accessory connected toa computing device; FIGS. 81B and 81C are the schematic diagrams of theoptical sensing accessory connected to a computing device.

FIG. 82A is a block diagram of a wireless optical sensing accessoryconnected to a computing device; FIG. 82B is a schematic diagram of thewireless optical sensing accessory connected to a computing device.

FIG. 83A is a block diagram of an optical sensing device; FIGS. 83B and83C are the schematic diagrams of the optical sensing device comprisingan optical sensor module and a wearable housing.

FIG. 84A is a schematic diagram of the optical sensing device connectedto an optical sensing accessory. FIG. 84B is a schematic diagram of theoptical sensing device connected to another sensing device.

FIG. 85A is a block diagram of a wireless optical sensing deviceconnected to another wireless optical sensing device; FIG. 85B is aschematic diagram of the wireless optical sensing device connected toanother wireless optical sensing device.

FIGS. 86A and 86B are the schematic diagrams of an application scenarioof using an optical sensing device to achieve multi-site measurement.

FIGS. 87A and 87B are the schematic diagrams of the optical sensingdevice having a bi-directional optical sensor module exposing the twocontact surfaces to two different surfaces of an optical sensing device.FIG. 87C is a partial cutaway view from side of an optical sensingdevice having a bi-directional sensing module. FIG. 87D is an enlargedview of FIG. 87C illustrating a bi-directional sensor module in anoptical sensing device having two contact surfaces facing twodirections.

FIG. 88 is a block diagram of a multi-site sensing accessory.

FIG. 89 is a block diagram of a multi-site sensing device.

FIG. 90 is a block diagram of a multi-site sensing system.

DETAILED DESCRIPTION

It will be appreciated that for simplicity and clarity of illustration,where appropriate, reference numerals have been repeated among thedifferent figures to indicate corresponding or analogous elements. Inaddition, numerous specific details are set forth in order to provide athorough understanding of the embodiments described herein. However, itwill be understood by those of ordinary skill in the art that theembodiments described herein can be practiced without these specificdetails. In other instances, methods, procedures and components have notbeen described in detail so as not to obscure the related relevantfeature being described. The drawings are not necessarily to scale andthe proportions of certain parts may be exaggerated to better illustratedetails and features. The description is not to be considered aslimiting the scope of the embodiments described herein.

Several definitions that apply throughout this disclosure will now bepresented.

The term “coupled” is defined as connected, whether directly orindirectly through intervening components, and is not necessarilylimited to physical connections. The connection can be such that theobjects are permanently connected or releasably connected. The term“outside” refers to a region that is beyond the outermost confines of aphysical object. The term “inside” indicates that at least a portion ofa region is partially contained within a boundary formed by the object.The term “substantially” is defined to be essentially conforming to theparticular dimension, shape or other word that substantially modifies,such that the component need not be exact. For example, substantiallycylindrical means that the object resembles a cylinder, but can have oneor more deviations from a true cylinder. The term “comprising” means“including, but not necessarily limited to”; it specifically indicatesopen-ended inclusion or membership in a so-described combination, group,series and the like.

The reflective optical sensor module is manufactured to emit light anddetect the reflected light from an object surface, and the receivedreflected light will be proportionally transduced into electricalsignal, such as a voltage, a current or a combination thereof. As shownin FIGS. 1A and 1B, the optical sensor module 10 comprises a lightsource 110, a first encapsulant 111 over the light source 110, aphotodetector 120, a second encapsulant 121 over the photodetector 120,and a partition 130. Each of the light source 110, the photodetector120, the first encapsulant 111, the second encapsulant 121, and thepartition 130 are mounted on a substrate 140. The optical sensor module10 may be fabricated in a single compact package. It is alsocontemplated that the optical sensor module 10 may employ discrete lightsource 110 and photodetector 120 that are separately packaged andmounted to one or more printed circuit boards (also referred to as“PCB”) depending on various design requirements. The exemplaryembodiments of each component are described as below.

A substrate 140 is configured to have components installed thereon andprovides mechanical or electrical connections between the components.Further, the substrate 140 provides mechanical support to the componentsof the optical sensor module 10 and interconnectivity between otherexternal electronic components and the optical sensor module 10. Inaddition, the first encapsulant 111 and the second encapsulant 121 ofthe optical sensor module 10 are also formed on the substrate 140. Inimplementation, the substrate 140 may be printed circuit board (PCB),metal core PCB (MCPCB), ceramic PCB, or direct bonded copper substrate(DBC).

Optoelectronic transducers can convert the signals between opticalsignals and electrical signals. The light source 110, which convertselectric power into radiant energy in a specific spectrum of wavelengths(for example, ultraviolet, visible, or infrared portions of thespectrum). The light source 110 may have electrical connections to aprinted circuit embedded in the substrate to receive triggering signalsand applied voltage from a microcontroller, a light source driver, or agated power source. In implementation, the optical sensor module 10 mayemploy one or more light emitting diodes (LED), organic light emittingdiodes (OLED), laser diodes (LD), or the like as light source 110. Forexample, the light source 110 of the optical sensor module 10 maycomprise one or more LEDs, each configured to emit light in the specificspectrum of wavelengths. It is contemplated that the light sources 110may further emit light in different spectrum of wavelengthssynchronously or asynchronously depending on various applications.

The photodetector 120, which detects and converts radiant energy in thespecific spectrum into electrical current or voltage, is mounted to thesubstrate 140. The photodetector should have a spectral response atleast active in a part of corresponding wavelengths of the light source110. The photodetector 120 may have electrical connections to a printedcircuit embedded in the substrate to convey the photocurrent to amicrocontroller, an operational amplifier, or an analogue front end. Inimplementation, the optical sensor module 10 may employ photodiode,phototransistor, photoresistor, photomultiplier, metal oxidesemiconductor (MOS), or the like as photodetector 120. The photodetector120 may detect the light in the specific spectrum of wavelengths emittedby the light source 110 or the light with a wavelength shift from thelight emitted by the light source. Accordingly, the photodetector 120converts the detected light into electrical signals. The photodetector120 may also detect light in a spectrum of wavelengths different fromthe specific spectrum of wavelength of the light source 110. Forexample, the fluorescent light emitted from an object surface afterreceiving the light emitted from the light source 110 may be detected bya photodetector 120. Furthermore, the photodetector 120 may also detectthe infrared light from an object surface, while the light source 110does not emit infrared light in one example. The photodetector 120 maycomprise a single or a plurality of photodiodes to extend the responsespectrum or to separately measure different wavelengths of receivedlight.

A partition 130 is mounted to the substrate 140 and is formed betweenthe light source 110 and the photodetector 120 for blocking the straylight directly from the light source 110 to the photodetector 120. Inaddition, the partition 130 may be formed of opaque material, whichreflects and/or absorbs light in a specific spectrum of wavelengthsemitted by the light source 110. Furthermore, an optical sensor modulemay have packaging walls 131 to prevent the ambient noise. As shown inthe FIGS. 1A and 1B, the packaging walls 131 of the optical sensormodule 10 may be formed around the light source 110 and thephotodetector 120. The packaging walls 131 may further providemechanical support when a cover 150 is applied in an optical sensormodule. In some examples, a part of the packaging wall 131 may bedisposed between the light source and the photodetector, and replace thefunction of the partition. The packaging wall may define an areasurrounding the light source, the partition, and the photodetector. Thepartition and the packaging wall may have similar or different materialdepending on the requirement of the capability of light blocking. Also,the partition and the packaging wall may be formed as a single entity oras multiple separate parts.

The encapsulants hermetically seal the optoelectronics for prolongingthe durability of the optoelectronics, and improving light extractionefficiency by mediating the high refractive index difference between theoptoelectronics and the environmental medium. The encapsulants shouldbe, at least partially, transparent so that it can be an adequate mediumof light propagation. In implementation, the material of theencapsulants may have lower refractive index than the optoelectronicshave and higher than the environment, such as air, water, or gel. Thematerial can be selected from silicone compound, or selected from clearpolymers, which can include polydimethylsiloxane (PDMS), polycarbonate(PC), or poly(methyl methacrylate) (PMMA).

The present technology has the features on the construction and theconfiguration of an encapsulant 111 covering the light source 110 or anencapsulant 121 covering the photodetector 120. The encapsulants 111,121 can be constructed using a single layer or more than one layer. Whena single layer construction manufactured by one kind of material isimplemented, the encapsulant may have one refractive index mediating theoptoelectronics and the environment. The refractive index differencebetween an optoelectronic transducer with a great refractive index andthe environment with low refractive index leads to poor light extractionor light receiving efficiency. An encapsulant generally has a refractiveindex between a great refractive index of an optoelectronic transducerand a low refractive index the environment, so that the light extractionor light receiving efficiency can be slightly improved.

The multilayer construction may be formed by multiple physical layerswith different refractive indices or may be formed as a single entitywith non-homogenous refractive index, such as a gradient refractiveindex. In one example, an encapsulant may be manufactured by stackingmultiple layers with different refractive indices. In other example, anencapsulant with one material may be applied with an external electricalfield during the manufacturing process, and resulting in the encapsulantwith multiple refractive index layers while no physical interfacespresented in the encapsulant. In one example, refractive indices of eachof the layers may decrease from proximal portion to distal portion whenthe encapsulant has a multilayer construction. For ease ofunderstanding, the illustrations of the encapsulants with multilayerconstruction, including physical layers or a single entity withnon-homogenous refractive index, may be depicted with separate line anddifferent hatchings. Without departing from the scope, the drawings arenot limited to the encapsulants with multilayer construction in multiplephysical layers. It has the advantage of reducing total internalreflection of emitting light by gradually mediating the high refractiveindex difference between light source 110 and the environmental mediumthe emitting surface, and, hence, improves the light extractionefficiency. As to the construction styles, presented as various kinds ofstacks, are engineered for specific requirements.

The surface of an encapsulant may be formed as a specific configuration;especially in the case of multiple layer construction, the interface ofany two layers may also be formed as a specific configuration. Thespecific configuration may be a microstructure or an optical directionalcomponent and the detail of the embodied configurations will bedescribed below. An encapsulant may have modifications in configurationand/or construction. A configuration of an encapsulant is a modificationof shape, contour, or inclination or any combination thereof. Aconfiguration may be a microstructure or an optical directionalcomponent. A microstructure may be a Fresnel lens or a diffractiveoptical element, while an optical directional component may be aninclined plane or a curvature lens. The configuration can be disposed onany interfaces between two adjacent layers in an encapsulant or on thesurface of an encapsulant. The surface of an encapsulant can be definedwith medial surface, top surface and lateral surface. The medial surfaceof an encapsulant is the outline substantially facing to the partition.The top surface of an encapsulant is the surface about parallel to theplane of the substrate. For example, the top surface of the firstencapsulant 111 is configured with a first microstructure 112, and thesecond encapsulant 121 may have a second microstructure 122. Inaddition, the second encapsulant 121, in order to improve the lightreceiving efficiency, may have different designs in the construction andconfiguration from the first encapsulant.

The surface of the encapsulants or the interface of any two layers maybe formed as a microstructure. For example, the top surface of theuppermost layer of the first encapsulant 111 is configured as amicrostructure 112 as illustrated in FIG. 1A. The encapsulant withmicrostructure(s) enhances the signal strength because the light isconcentrated toward an intended direction while the light passes throughthe microstructure of the encapsulant. The microstructure may be arefractive microstructure or a diffractive microstructure. A refractivemicrostructure follows the law of refraction and is engineered to directthe light rays toward an object surface so that most reflected light mayreach the photodetector 120. For example, a Fresnel lens microstructureeffectively divides the continuous surface of a standard lens into a setof surfaces resulting in a substantial reduction in thickness. Adiffractive microstructure re-distributes the propagating light waveenergy on the projection plane. For example, a diffractive opticalelement (DOE) microstructure may be engineered to achieve a specificlight distribution profile. A refractive microstructure or a diffractivemicrostructure is able to concentrate the emitting light from the lightsource 110 toward a desired direction so that the effective signals areimproved.

The optical sensor module 10 is a compact packaged module comprising ofa light source 110, a photodetector 120, an encapsulant, a partition130, and a substrate 140. The present technology improves theperformance of the optical sensor module 10 achieved by enhancing thelight extraction efficiency, directing the light path, or reducing thestray light. An optical sensor module can be embodied as a simplecomposition with one light emitting diode (LED) and one siliconphotodiode both mounted on a printed circuit board as a substrate 140.Each of the LED and the silicon photodiode are hermetically andseparately sealed by epoxy encapsulants. In an example for measuringoxygenation of biological tissue, wavelengths in infrared and redregions are required. Therefore, one red LED and one infrared LED may bemounted on the same sensor module 10. In other examples, a single LEDcan be implemented that emits light in the infrared and red regions ofthe spectrum. In the embodiments described later in the text, one lightsource 110 and one photodetector 120 are used as examples. In otherimplementations that are within the scope of the present disclosure, thenumber and the arrangement of the light sources 110 and photodetectors120 may be modified.

As shown in FIG. 1A, the general construction of the optical sensormodule 10 is presented in a schematic cross sectional view. The opticalsensor module 10 comprises a light source 110, a photodetector 120 and apartition 130 located between the light source and the photodetector120. Each of the light source 110, the photodetector 120, the firstencapsulant 111, the second encapsulant 121, and the partition 130 aremounted on a substrate 140. The first encapsulant 111 covers the lightsource 110, while the second encapsulant covers the photodetector 120.The optical sensor module has at least a part of the partition 130 beingspaced apart from at least one of the first encapsulant 111 and thesecond encapsulant 121 by a predetermined distance. Furthermore, amicrostructure 112 formed on an outer profile of at least one of thefirst encapsulant 111 and the second encapsulant 121. In FIG. 1B, themedial surface 310 of the first encapsulant 111 may have an inclinedplane with an inclined angle 315 between the substrate 140 and themedial surface 310. In one example, the inclined angle 315 is fortydegrees when the partition 130 is 0.6 millimeter height and the firstencapsulant is about the same height with the partition 130.

In one embodiment of the present disclosure, as shown in FIGS. 2-5, thelight source 110 is illustrated as two independent LEDs sealed in afirst encapsulant 111, and the photodetector 120 may be a photodiodesealed in a second encapsulant 121. In addition, a partition 130 islocated between the LEDs and the photodiode. An optical sensor modulemay have the packaging wall 131 extending around the encapsulants toreduce ambient stray light. The surface of both encapsulants have apredetermined surface configuration to enhance SNR. For ease ofpresentation, the medial surface 310 is the surface facing the partition130 located between the light source 110 and the photodetector 120, thelateral surface is the surface facing toward the opposite side, and thetop surface is about parallel to the substrate plane. The medial surface310 of the first encapsulant 111 may have an inclined plane or acurvature lens or the combination thereof. An inclined plane may have aninclined angle 315 between the surface of the encapsulant and the planeof the substrate. The inclined angle may be around ninety degrees totwenty degrees. Therefore, light emitted from the light source is lessshed onto the partition 130 to avoid light leakage direct from the lightsource 110 to the photodetector 120.

As illustrated in FIG. 2A, the light source 110 is sealed in the firstencapsulant 111, and the top surface of the first encapsulant 111 isformed as a microstructure 112. Additionally, the photodetector 120 issealed in the second encapsulant 121, and the top surface of the secondencapsulant 121 is formed as a microstructure 122. In the crosssectional view (FIG. 2B) and oblique view (FIG. 2C), both the firstencapsulant 111 and the second encapsulant 121 are separatelyconstructed of a single layer in trapezoid shape. The medial and lateralsurfaces of both the first encapsulant 111 and second encapsulant 121have an angle. It is contemplated that the configuration and thematerial of the second encapsulant 121 may differ from the ones of thefirst encapsulant 111, in order to meet the requirements of the lightreceiving efficiency for specific applications.

As illustrated in FIG. 3A, the light source 110 is sealed in the firstencapsulant 111, and the top surface of the first encapsulant 111 isformed as a microstructure 112. Additionally, the photodetector 120 issealed in the second encapsulant 121, and the top surface of the secondencapsulant 121 is formed as a microstructure 122. In the crosssectional view (FIG. 3B) and oblique view (FIG. 3C), both the firstencapsulant 111 and the second encapsulant 121 are separatelyconstructed of a single layer in trapezoid style. The medial and lateralsurfaces of both the first 111 and second 121 encapsulants have apredetermined inclined angle 315. Additionally, the medial surface 310of the first encapsulant 111 has a tilted at a larger angle, so that thelight emitted from the medial surface 310 is mostly allowed to passtoward the upper part of the medial surface. In at least one example,the configuration and the material of the second encapsulant 121 maydiffer from the ones of the first encapsulant 111. The inclined angle ofan inclined plane or a curvature lens may be larger or smaller than themedial surface 310 of the second encapsulant 121.

As illustrated in FIG. 4A, the light source 110 is sealed in the firstencapsulant 111, and the top surface of the first encapsulant 111 isformed as a microstructure 112. Additionally, the photodetector 120 issealed in the second encapsulant 121, and the top surface of the secondencapsulant 121 is formed as a microstructure 122. In the crosssectional view (FIG. 4B) and oblique view (FIG. 4C), both the firstencapsulant 111 and the second encapsulant 121 are separatelyconstructed of a single layer in trapezoid style. The medial and lateralsurfaces of both the first 111 and second 121 encapsulants have aninclined angle.

As illustrated in FIG. 5A, the light source 110 is sealed in the firstencapsulant 111, and the top surface of the first encapsulant 111 isformed as a microstructure 112. Additionally, the photodetector 120 issealed in the second encapsulant 121, and the top surface of the secondencapsulant 121 is formed as a microstructure 122. In the crosssectional view (FIG. 5B) and oblique view (FIG. 5C), both the firstencapsulant 111 and the second encapsulant 121 are separatelyconstructed of a single layer in trapezoid style with a curved medialsurface. The lateral surfaces of both the first 111 and second 121encapsulants have a tilting angle. Specifically, the medial surfaces ofboth the first encapsulant 111 and the second encapsulant 121 have acurved medial surface, so that the extraction light from the medialsurface is enhanced toward the upper part of the medial surface and morereflected light is received from the upper part of the medial surface ofthe second encapsulant 121. In at least one example, the configurationand the material of the second encapsulant 121 may differ from the onesof the first encapsulant 111. The inclined angle of the medial surfaceof the first encapsulant 111 may be different from the inclined angle ofthe medial surface of the second encapsulant 121. Furthermore, theoptical sensor module may have an inclined plane on the medial surfaceof the first encapsulant 111, while a curvature lens on the medialsurface of the second encapsulant 121.

In the embodiments shown in FIG. 6, the optical sensor modules 10 may beapplied directly on the object surface 190 to have the top surfaces ofthe encapsulants contact the object surface 190. The object surface 190may be the surface of a biological tissue, such as a skin or a mucosa.In FIGS. 6A and C, the object surface 190 contacts as much the topsurface of the encapsulants as possible to achieve better SNR. In thecross sectional view FIG. 6B, the object surface 190 directly contactsthe top surface of the encapsulants.

In one embodiment of the present disclosure, as shown in FIGS. 7-11, thelight source 110 may include two LEDs sealed in a first encapsulant 111,and the photodetector 120 may be a photodiode sealed in a secondencapsulant 121. Each top surface of the encapsulants is configured as amicrostructure. The optical sensor module 10 may further comprise acover 150 above the first encapsulant 111 and the second encapsulant121. The cover 150 may be located, during application, between theencapsulants and the object surface 190. The cover 150 serves as acontact interface between the object surface 190 (for example, abiological tissue surface or a skin surface) to increase the durabilityof the optical sensor module 10 and the consistency of measurement. Thecover 150 provide a contact surface with the object surface 190 and keepthe optical path clear from the water or dust. The cover 150 may beintegrated as a part of the optical sensor module 10 or may be a part ofthe housing of the optical sensor device. As shown in FIGS. 7A and C,the optical sensor module 10 may further comprise a cover 150 above thefirst encapsulant 111 and the second encapsulant 121. In addition, theremay be a slight gap between the cover 150 and the top surface of theencapsulants to reduce light leakage via the cover 150 (FIG. 7B).

In one embodiment as shown in FIG. 8A, the optical sensor module 10comprises a cover 150. In addition, the internal surface or the externalsurface of the cover 150 may be coated with a thin film 151. The thinfilm 151 may be an anti-reflective thin film (such as index-matchingthin film or interference thin film), or an anti-scratch thin film (suchas polyethylene terephthalate, or silicon hard coating). As shown inFIG. 8B, the external surface of cover 150 is covered with ananti-scratch thin film 151 and the internal surface of the cover 150 iscovered with an anti-reflective thin film 151. In at least one example,the two surfaces may be covered with same kind of thin film 151 or oneof the surfaces of the cover 150 may have no thin film. It iscontemplated that the cover 150 may be coated with a filter thin film toclear out undesired range of lights.

In one embodiment, the optical sensor module 10 may comprise a thin film160 covering an encapsulant. With thin film technology, the SNR of theoptical signals may be further improved. The thin film 160 may be ananti-reflective thin film or a filter thin film. The anti-reflectivethin film may be an index-matching film (for example, Rayleigh film) oran interference film to improve light extraction efficiency by reducingFresnel reflection at the interface between the encapsulants and theenvironmental medium. The filter thin film may be a long-pass filter, ashort-pass filter, or a band-pass filter to clear down the full width athalf maximum (FWHM) of the emitting light or filter out the noise fromundesired wavelengths. The optical sensor module 10 may further comprisea thin film 160 covering the surface of the first encapsulant 111 and/orthe second encapsulant 121.

As shown in FIG. 9, both the surfaces of the first encapsulant 111 andthe second encapsulant 121 are coated with a thin film 160. The thinfilm 160 of the first encapsulant 111 is embodied as an anti-reflectivethin film (FIG. 9B) and the thin film 160 of the second encapsulant 121is embodied as a band-pass filter thin film (FIG. 9C). Theanti-reflective thin film improves the light extraction efficiency andthe band-pass filter thin film reduces noise. In at least one example,the thin film 160 of the first encapsulant 111 is embodied as aband-pass filter thin film and the thin film 160 of the secondencapsulant 121 is embodied as an anti-reflective thin film, so that theFWHM of the emitting light has a clear cut-off wavelength and thephotodiode detects the filtered signals within a specific range ofwavelengths. In the application of fluorescence detection long-passfilter thin film maybe applied to the second encapsulant 121 to acquirea clear fluorescent signal avoiding the excitation light. Also, theoptical sensor module 10 may have a cover 150 as shown in FIG. 10A andthin films 160 over the first encapsulant 111 and the second encapsulant121 (FIGS. 10 B and C). Furthermore, the optical sensor module 10 mayfurther comprise both a cover 150 coated with thin films 151 and thethin films 160 covering the encapsulants (FIG. 11A). The thin film 151of external surface of the cover 150 may be an anti-scratch thin filmand the one 151 of the internal surface may be as an anti-reflectivethin film (FIG. 11B). The thin film 160 of the first encapsulant 111 maybe as an anti-reflective thin film (FIG. 11 C) and the thin film 160 ofthe second encapsulant 121 may be as a band-pass filter thin film (FIG.11D).

The light source 110 and the photodetector 120 in an optical sensormodule 10 may be arranged in a two dimensional pattern in order toincrease SNR as shown in FIGS. 12-15. In general, the light source 110may be a set of multiple light emitters with different wavelengthsencapsulated in the central region; the photodetector 120 may be asingle entity surrounding the light source 110, or may be multiplephotodetectors 120 located around the central light source 110. Thecentral light source 110 is covered with a first encapsulant 111 andeach photodetector 120 is covered with a second encapsulant 121 (FIG.12A). In cross sectional view (FIG. 12B) and oblique view (FIG. 12C),the photodetector 120 sits beside the light source 110, and the opticalinsulating partition 130 separates the light source 110 andphotodetector 120. Furthermore, the top surface of the first encapsulant111 is configured as a microstructure 112. The first microstructure 112is capable of guiding the emitting light outward so that more reflectedlight reaches the surrounding photodetector 120. Also, the top surfaceof the second encapsulant 121 is configured as a microstructure 122 toimprove the light receiving efficiency. The microstructure 122 of thesecond encapsulant 121 may have different designs from the one of thefirst encapsulant 111 to improve SNR. In at least one example, theconfiguration of the encapsulants (for example, microstructure), thesurface thin film 160 covering the encapsulants, and the cover 150mentioned in FIG. 7-11 may be applied to the two dimensional patternsensor module 10 described in FIG. 12-15.

In one embodiment of the present disclosure, as shown in FIG. 13, thelight source 110 is illustrated as two independent LEDs sealed in afirst encapsulant 111, and the photodetector 120 may be a single annularphotodiode sealed in a second encapsulant 121. In addition, an annularpartition 130 is located between the LEDs and the photodiode to reducedirect light leakage from the light source 110 to the photodetector 120;a second annular partition 130 may reside around the second encapsulant121 to reduce ambient stray light.

As illustrated in FIG. 13A, the optical sensor module 10 can be embodiedas a single annular photodiode surrounding the central light source 110.The central light source 110 may comprise two LEDs having differentemitting wavelength(s), and the both of the two LEDs are covered withthe first encapsulant 111. The photodetector 120 may be a single pieceof annular silicon photodiode surrounding the central light source 110,and the annular photodiode is covered with the annular secondencapsulant 121. The top surface of the first encapsulant 111 isconfigured as a microstructure 112, and the first microstructure 112 maybe in a concentric circular pattern. Additionally, the top surface ofthe second encapsulant 121 is configured as a second microstructure 122,which can be a concentric circular pattern. In the cross sectional view(FIG. 13B) and oblique view (FIG. 13C), both the first encapsulant 111and the second encapsulant 121 are separately constructed of intrapezoid shape, which features the narrower upper part of theencapsulant. The arrangement of the first encapsulant and the secondencapsulants may be a reflectional symmetric patterns, such as linear,elliptic, hexagonal, or polygonal. The patterns may have some extent ofSNR improvement due to the photodetector 120 locating beside the lightsource 110. In at least one example, the construction, themicrostructure, the material of the second encapsulant 121 may differfrom the ones of the first encapsulant 111, in order to meet therequirements of the light receiving efficiency for specificapplications. For example, the second encapsulants have multilayerconstruction with microstructures on the top surfaces.

In one embodiment of the present disclosure, as shown in FIG. 14, thelight source 110 is illustrated as two independent LEDs sealed in thefirst encapsulant 111, and the photodetector 120 may be a group ofseparate photodiodes, each sealed in a second encapsulant 121. Inaddition, a partition 130 is located around the LEDs to reduce directcrosstalk; the photodiodes may have a packaging wall 131 around thesecond encapsulants 121 to reduce both direct crosstalk and ambientstray light.

As illustrated in FIG. 14A, the optical sensor module 10 may be embodiedas multiple photodiodes surrounding the central light source 110. Thecentral light source 110 may comprise two LEDs of different emittingwavelength, and the LEDs are covered with a first encapsulant 111. Thephotodetectors 120 may be a group of square photodiodes annularlyarranged around the central light source 110, and each photodiode iscovered with a second encapsulant 121. Also, a hexagonal partition 130is located around the LEDs to reduce direct light leakage; photodiodesmay have a lateral packaging wall 131 around the second encapsulants 121to reduce and ambient stray light. In the cross sectional view (FIG.14B) and oblique view (FIG. 14C), both the first encapsulant 111 and thesecond encapsulant 121 are separately constructed of in trapezoid shape,which features the narrower upper part of the encapsulant. The topsurface of the first encapsulant 111 is configured as a microstructure112, and the first microstructure 112 may be embodied as a concentriccircular pattern. Additionally the top surface of the second encapsulant121 is configured as a microstructure 122, and the second microstructure122 may be embodied as a concentric circular pattern. While theillustrated pattern is a hexagonal pattern, the present disclosureincludes other types of polygonal patterns, such as triangular,pentagonal, or octagonal. All other patterns may have some extent of SNRimprovement due to the photodetectors 120 locating beside the lightsource 110. In at least one example, the construction, themicrostructure, the material of the second encapsulants 121 may differfrom the ones of the first encapsulant 111, in order to meet therequirements of the light receiving efficiency for specificapplications.

As illustrated in FIG. 15A, the optical sensor module 10 may be embodiedas multiple photodiodes surrounding the central light source 110. Thecentral light source 110 may comprise two LEDs of different emittingwavelength, and the LEDs is covered with a first encapsulant 111. Thephotodetectors 120 may be a group of square photodiodes annularlyarranged around the central light source 110, and each photodiode iscovered with a second encapsulant 121. Additionally, a square partition130 is located around the light source 110 and the photodetectors 120may have a lateral packaging wall 131 around the second encapsulants 121to reduce ambient stray light. In the cross sectional view (FIG. 15B)and oblique view (FIG. 15C), both the first encapsulant 111 and thesecond encapsulant 121 are separately constructed with the feature ofthe narrower upper part of the encapsulant. The top surface of the firstencapsulant 111 is configured as a microstructure 112, and the firstmicrostructure 112 may be embodied as a concentric circular pattern.Additionally, the top surface of the second encapsulant 121 isconfigured as a microstructure 122, and the second microstructure 122may be embodied as a concentric circular pattern. Without departing fromthe scope of the disclosure the arrangement pattern of an optical sensormodule may be other polygonal patterns, such as triangular, pentagonal,or octagonal. All other patterns may have some extent of SNR improvementdue to the photodetectors 120 locating beside the light source 110. Inat least one example, the construction, the microstructure, the materialof the second encapsulants 121 may differ from each other or the ones ofthe first encapsulant 111.

In the present disclosure, the optical sensor module 10 may employ theencapsulant 111 with multiple refractive index layers over the lightsource 110 for improving the light extraction efficiency or may employthe encapsulant 111 with multiple refractive index layers over thephotodetector 120 for improving reflected light receiving efficiency.The optical sensor module 10 enhances the signal strength because thetotal internal reflection of the emitted light is reduced while thelight passes through the encapsulant 111 layer by layer outward from thelight source 110. For example, the first encapsulant 111, formed on thesubstrate 140 over the light source 110, includes multiple refractiveindex layers. Multiple refractive index layers may be constructed bystacking multiple physical layers with different refractive indices ormay be constructed by a single entity of gradient refractive index. Therefractive index of each layer of the first encapsulant 111 decreaseslayer by layer from lower layers to upper layers. As shown in the FIG.16A, the first encapsulant 111 includes a plurality of layers (twolayers are illustrated) in which each layer is formed of material thatallows the emitted light by the light source 110 to pass through. Forexample, the refractive index (n₁) of the lower layer (bottom layer) ofthe first encapsulant 111, formed directly over the light source 110, ishigher than the refractive index (n₂) of the upper layer (top layer),which abuts the top surface of the bottom layer, of the firstencapsulant 111. With respect to conventional encapsulant with only asingle refractive index layer over the light source 110, the decreasingrefractive index of the adjacent layers of the first encapsulant 111,gradually mediates a drastic refractive index difference between thelight source 110 and the environmental medium. Generally, the refractiveindex of an optoelectronic transducer is greater than three, while therefractive index of ambient air is about one. The critical angle (θc_arcsin(n₂/n₁)) occurs at the interface of adjacent layers of the firstencapsulant 111 has a significant increase compared to a bare lightsource 110 alone or a light source 110 merely with a single layer ofencapsulant. Also, the critical angle at the interface between the toplayer of the first encapsulant 111 and the environmental mediumsurrounding the optical sensor module 10 is widened. The amount of thetotal internal reflection is reduced while the light emitted by thelight source 110 sequentially passes through the decreasing refractiveindices of the multiple layers in the first encapsulant 111.Consequently, the optical sensor module 10 enhances the signal strengthby improving the light extraction efficiency according to the firstencapsulant 111 with a plurality of refractive index layers. Similarly,a second encapsulant with multiple refractive index layers may be formedover a photodetector 120 to improve light receiving efficiency for thesignal light coming from the light source 110 and reflected by an objectsurface.

As shown in FIG. 16A, the general construction of the optical sensormodule 10 is presented in a schematic cross sectional view. The opticalsensor module 10 comprises a LED, a silicon photodiode, and a partition130 located between the LED and the photodetector 120, wherein all theabove are mounted on a substrate 140. The first encapsulant 111 coversthe light source 110, while the second encapsulant 121 covers thephotodetector 120. In the embodiments, an encapsulant may havemodifications in configuration and construction. For example, the topsurface of the first encapsulant 111 is configured as a firstmicrostructure 112, and the second encapsulant 121 may have a secondmicrostructure 122. The first encapsulant 111 is constructed withmultiple refractive index layers, and a double layer construction isillustrated in FIG. 16A, while three or more layers may be realized. Theinterface between any two layers may also have a configuration, such asa microstructure 112 or an optical directional component 113. Similarly,the second encapsulant 121 may also be constructed with multiple layersand may have a surface microstructure 122 or a configuration (forexample, a curvature lens) at the interface between any two layers. Inaddition, the second encapsulant 121, in order to improve the lightreceiving efficiency, may have different designs in the construction andconfiguration from the first encapsulant 111.

FIG. 16B-E shows the relation between refractive index within anencapsulant with multiple refractive index layers and distance from thesubstrate. In FIG. 16B, a dot line connecting between x0 and x1indicates the corresponding measurements of refractive index, where x0represents one of the most proximal portions in an encapsulant and x1represents one of the most distal portions in an encapsulant. FIG. 16C-Eshows the refractive index function of distance from the substrate. Inone example as illustrated in FIG. 16C, the encapsulant with multiplerefractive index layers has gradient refractive index. In one example asillustrated in FIG. 16D, the encapsulant with multiple refractive indexlayers has discrete refractive indices. In one example as illustrated inFIG. 16E, the encapsulant with multiple refractive index layers hasmultiple physical layers with gradient refractive index. In addition,the gradient refractive index may be linear or non-linear to thedistance. The refractive index function of distance may be monotonicallydecreasing. In addition, non-monotonicity of the refractive indexfunction of distance may be tolerable.

In one embodiment of the present disclosure, as shown in FIGS. 17-19,the light source 110 is illustrated as two independent LEDs sealed in afirst encapsulant 111, and the photodetector 120 may be a photodiodesealed in a second encapsulant 121. The first encapsulant 111 and/or thesecond encapsulant 121 is constructed with multiple refractive indexlayers, and the top surface of the first encapsulant 111 or the secondencapsulant 121 is configured as a microstructure 112.

As illustrated in FIG. 17A, the top surface of the upper layer of thefirst encapsulant 111 is configured as a microstructure 112, and themicrostructure 112 is embodied as a set of concentric arcs concavetoward the photodiode, while a photodiode is sealed in the secondencapsulant 121 without a microstructure. In the cross sectional view(FIG. 17B) and oblique view (FIG. 17C), both the first encapsulant 111and the second encapsulant 121 are separately constructed of a stack ofmultiple layers in Babel Tower style, which features the distal portionof the encapsulant is narrower than the proximal portion. Also, themultiple refractive index layers has different refractive indicesarranged in a decreasing fashion from proximal layers to distal layers.

As illustrated in FIG. 18A, the top surface of the distal layer of thefirst encapsulant 111 is configured as a microstructure 112, and themicrostructure 112 is embodied as a set of concentric arcs concavetoward the photodiode, while a photodiode is sealed in the secondencapsulant 121 without a microstructure. In the cross sectional view(FIG. 18B) and oblique view (FIG. 18C), both the first encapsulant 111and the second encapsulant 121 are separately constructed in multiplerefractive index layers in a pancake stack style, which features thecircumferential flank sides of the multi-layer encapsulant abutting thepartition 130 and the packaging wall 131. The multiple refractive indexlayers has different refractive indices arranged in a decreasing fashionfrom lower layers to upper layers.

As illustrated in FIG. 19A, the top surface of the distal layer of thefirst encapsulant 111 is configured as a microstructure 112, and themicrostructure 112 is embodied as a set of concentric arcs concavetoward the photodiode, while a photodiode is sealed in the secondencapsulant 121 without a microstructure. In the cross sectional view(FIG. 19B) and oblique view (FIG. 19C), both the first encapsulant 111and the second encapsulant 121 are separately constructed in multiplerefractive index layers in a cup-stacking style, which features theupper layer embracing the adjacent lower layer. The multiple refractiveindex layers has different refractive indices arranged in a decreasingfashion from lower layers to upper layers.

It is contemplated that the second encapsulant 121 may be constructed asa single entity (single layer) or a multi-layer stack, and constructedin various stacking styles. The construction and the material of thesecond encapsulant 121 may differ from the ones of the first encapsulant111, in order to meet the requirements of the light receiving efficiencyfor specific applications.

In one embodiment of the present disclosure, as shown in FIGS. 20-22,the light source 110 is illustrated as two independent LEDs sealed in afirst encapsulant 111, and the photodetector 120 may be a photodiodesealed in a second encapsulant 121. The first encapsulant 111 isconstructed with a multiple refractive index layers, and the top surfaceof the first encapsulant 111 is configured as a microstructure 112.Also, the second encapsulant 121 is constructed with multiple refractiveindex layers, and the top surface of the second encapsulant 121 isconfigured as a microstructure 122.

As illustrated in FIG. 20A, the top surface of the first encapsulant 111is configured as a microstructure 112, and the microstructure 112 isembodied as a set of concentric arcs concave toward the photodiode.Additionally, the top surface of the second encapsulant 121 isconfigured as a microstructure 122, which is embodied as a set ofconcentric circles. In the cross sectional view (FIG. 20B) and obliqueview (FIG. 20C), both the first encapsulant 111 and the secondencapsulant 121 are separately constructed of multiple refractive indexlayers in Babel Tower style. Also, the multiple refractive index layershas different refractive indices arranged in a decreasing fashion fromlower layers to upper layers. It is contemplated that the secondencapsulant 121 may be constructed as a single entity (single layer) ora multi-layer stack, and constructed in various stacking styles. Theconstruction and the material of the second encapsulant 121 may differfrom the ones of the first encapsulant 111, in order to meet therequirements of the light receiving efficiency for specificapplications.

As illustrated in FIG. 21A, the top surface of the upper layer of thefirst encapsulant 111 is configured as a microstructure 112, and themicrostructure 112 is embodied as a set of concentric arcs concavetoward the photodiode. Additionally, the top surface of the secondencapsulant 121 is configured as a microstructure 122, and themicrostructure 122 is embodied as a set of concentric circles. In thecross sectional view (FIG. 21B) and oblique view (FIG. 21C), both thefirst encapsulant 111 and the second encapsulant 121 are separatelyconstructed in multiple refractive index layers in a pancake stackstyle, which features the flank sides of the multi-layer encapsulantabutting the packaging wall 131. Also, the multiple refractive indexlayers has different refractive indices arranged in a decreasing fashionfrom lower layers to upper layers.

As illustrated in FIG. 22A, the top surface of the upper layer of thefirst encapsulant 111 is configured as a microstructure 112, and themicrostructure 112 is embodied as a set of concentric arcs concavetoward the photodiode. Additionally, the top surface of the secondencapsulant 121 is configured as a microstructure 122, and themicrostructure 122 is embodied as a set of concentric circles. In thecross sectional view (FIG. 22B) and oblique view (FIG. 22C), both thefirst encapsulant 111 and the second encapsulant 121 are separatelyconstructed in multiple refractive index layers in a cup-stacking style.Also, the multiple refractive index layers construction has differentrefractive indices arranged in a decreasing fashion from lower layers toupper layers.

In one embodiment of the present disclosure, as shown in FIGS. 23-25,the light source 110 is illustrated as two independent LEDs sealed in afirst encapsulant 111, and the photodetector 120 may be a photodiodesealed in a second encapsulant 121. The first encapsulant 111 isconstructed with multiple refractive index layers, and one interface ofany two adjacent layers of the first encapsulant 111 is configured as amicrostructure 112. Also, one interface of any two adjacent layers ofthe second encapsulant 121 may be configured as a microstructure 122.

As illustrated in FIG. 23A, one interface of any two adjacent layers ofthe first encapsulant 111 is configured as a microstructure 112, and themicrostructure 112 is embodied as a set of concentric arcs concavetoward the photodiode. Additionally, one of the interface of any twoadjacent layers of the second encapsulant 121 is configured as amicrostructure 122, and the microstructure 122 is embodied as a set ofconcentric circles. In the cross sectional view (FIG. 23B) and obliqueview (FIG. 23C), both the first encapsulant 111 and the secondencapsulant 121 are separately constructed with multiple refractiveindex layers in Babel Tower style. Also, the multiple refractive indexlayers construction has different refractive indices arranged in adecreasing fashion from lower layers to upper layers.

As illustrated in FIG. 24A, one interface of any two adjacent layers ofthe first encapsulant 111 is configured as a microstructure 112, and themicrostructure 112 is embodied as a set of concentric arcs concavetoward the photodiode. Additionally one interface of any two adjacentlayers of the second encapsulant 121 is configured as a microstructure122, and the microstructure 122 is embodied as a set of concentriccircles. In the cross sectional view (FIG. 24B) and oblique view (FIG.24C), both the first encapsulant 111 and the second encapsulant 121 areseparately constructed multiple refractive index layers in a pancakestack style.

As illustrated in FIG. 25A, one interface of any two adjacent layers ofthe first encapsulant 111 is configured as a microstructure 112, and themicrostructure 112 is embodied as a set of concentric arcs concavedtoward the photodiode. Additionally, one interface of any two adjacentlayers of the second encapsulant 121 is configured as a microstructure122, which is embodied as a set of concentric circles. In the crosssectional view (FIG. 25B) and oblique view (FIG. 25C), both the firstencapsulant 111 and the second encapsulant 121 are separatelyconstructed with multiple refractive index layers in a cup-stackingstyle. Also, the multiple refractive index layers construction hasdifferent refractive indices arranged in a decreasing fashion from lowerlayers to upper layers.

In one embodiment of the present disclosure, as shown in FIGS. 26-28,the light source 110 is illustrated as two independent LEDs sealed in afirst encapsulant 111, and the photodetector 120 may be a photodiodesealed in a second encapsulant 121. The first encapsulant 111 isconstructed with multiple refractive index layers, and multipleinterfaces of any two adjacent layers of the first encapsulant 111 isconfigured as a microstructure 112.

As illustrated in FIG. 26A, the first encapsulant 111 has multiplemicrostructures 112 formed as the top surface of the uppermost layer andformed as one interface of the adjacent layers inside, and themicrostructure 112 is embodied as a set of concentric arcs concavetoward the photodetector 120, while the second encapsulant 121 may beconstructed with multiple refractive index layers without amicrostructure. In the cross sectional view (FIG. 26B) and oblique view(FIG. 26C), both the first encapsulant 111 and the second encapsulant121 are separately constructed with multiple refractive index layers inBabel Tower style. Also, the multiple refractive index layersconstruction has different refractive indices arranged in a decreasingfashion from lower layers to upper layers. It is contemplated that thesecond encapsulant 121 may also have microstructures on the top surfaceand/or at one interface between any layers.

As illustrated in FIG. 27A, the first encapsulant 111 has multiplemicrostructures 112 formed as the top surface of the uppermost layer andformed as one interface of the adjacent layers inside, and themicrostructure 112 is embodied as a set of concentric arcs concavetoward the photodetector 120, while the second encapsulant 121 may beconstructed with multiple refractive index layers without amicrostructure. In the cross sectional view (FIG. 27B) and oblique view(FIG. 27C), both the first encapsulant 111 and the second encapsulant121 are separately constructed of a stack of multiple layers in apancake stack style, which features the flank sides of the multi-layerencapsulant abutting the packaging wall 131. Also, the multi-layerconstruction has different refractive indices arranged in a decreasingfashion from lower layers to upper layers.

As illustrated in FIG. 28A, the first encapsulant 111 has multiplemicrostructures 112 formed as the top surface of the uppermost layer andformed as one interface of the adjacent layers inside, and themicrostructure 112 is embodied as a set of concentric arcs concavetoward the photodetector 120, while the second encapsulant 121 may beconstructed with multiple refractive index layers without amicrostructure. In the cross sectional view (FIG. 28B) and oblique view(FIG. 28C), both the first encapsulant 111 and the second encapsulant121 are separately constructed of a stack of multiple layers in acup-stacking style, which features the upper layer embracing theadjacent lower layer. Also, the multi-layer construction has differentrefractive indices arranged in a decreasing fashion from lower layers toupper layers.

In the examples of the present disclosure, the light source 110 isillustrated as two independent LEDs sealed in a first encapsulant 111,and the photodetector 120 may be a photodiode sealed in a secondencapsulant 121. The first encapsulant 111 is constructed with multiplerefractive index layers, and at least one interface of any two adjacentlayers of the first encapsulant 111 is configured as a microstructure112. Also, the second encapsulant 121 is constructed with multiplerefractive index layers, and at least one interface of any two adjacentlayers of the second encapsulant 121 is configured as a microstructure122.

As illustrated in FIG. 29A, the first encapsulant 111 has multiplemicrostructures 112 formed as the top surface of the first encapsulant111 and formed as one interface of the adjacent layers and themicrostructure 112 is embodied as a set of concentric arcs concavetoward the photodetector 120. Additionally, a photodiode is sealed inthe second encapsulant 121 with multiple microstructures 122 formed asthe top surface of the second encapsulant 121 and formed as oneinterface of the adjacent layers, and each microstructure 122 isembodied as a set of concentric circles. In the cross sectional view(FIG. 29B) and oblique view (FIG. 29C), both the first encapsulant 111and the second encapsulant 121 are separately constructed of multiplerefractive index layers in Babel Tower style. Also, the multi-layerconstruction has different refractive indices arranged in a decreasingfashion from lower layers to upper layers.

As illustrated in FIG. 30A, the first encapsulant 111 has multiplemicrostructures 112 formed as the top surface of the first encapsulant111 and formed as one interface of the adjacent layers and themicrostructure 112 is embodied as a set of concentric arcs concavetoward the photodetector 120. Additionally, a photodiode is sealed inthe second encapsulant 121 with multiple microstructures 122 formed asthe top surface of the second encapsulant 121 and formed as oneinterface of the adjacent layers, and each microstructure 122 isembodied as a set of concentric circles. In the cross sectional view(FIG. 30B) and oblique view (FIG. 30C), both the first encapsulant 111and the second encapsulant 121 are separately constructed with multiplerefractive index layers in a pancake stack style.

As illustrated in FIG. 31A, the first encapsulant 111 has multiplemicrostructures 112 formed as the top surface of the first encapsulant111 and formed as one interface of the adjacent layers and themicrostructure 112 is embodied as a set of concentric arcs concavetoward the photodetector 120. Additionally, a photodiode is sealed inthe second encapsulant 121 with multiple microstructures 122 formed asthe top surface of the second encapsulant 121 and formed as oneinterface of the adjacent layers, and each microstructure 122 isembodied as a set of concentric circles. In the cross sectional view(FIG. 31B) and oblique view (FIG. 31C), both the first encapsulant 111and the second encapsulant 121 are separately constructed with multiplerefractive index layers in a cup-stacking style.

An optical directional component is a geometric optical component havinga distinct refractive index from adjacent substances. Light refractionoccurs when incident light travels through the refraction interface atan incident angle other than normal incidence. The refraction interfaceis a flat or curved plane and the inclined angle and the curvature ofthe plane is designed to meet the requirements. In one example, theoptical directional component may be a curvature lens configured todirect the light path so that the SNR is further improved. The curvaturelens may be configured at one interface of any adjacent layers in theencapsulant with multiple refractive index layer or may be configured onthe top surface of an encapsulant. The shape of a curvature lens may bea parabolic plane, a spherical plane, or a polygonal plane.

As illustrated in FIG. 32A, the first encapsulant 111 has theconfigurations as a microstructure 112 formed as the top surface of theuppermost layer. In addition, one interface of the first encapsulant 111with multiple refractive index layers may be configured as a curvaturelens 113. The microstructure 112 is embodied as a set of concentric arcsconcave toward the photodiode and the curvature lens 113 is embodied asa parabolic surface concave to the light source 110, while a photodiodeis sealed in the second encapsulant 121 without a microstructure. In thecross sectional view (FIG. 32B) and oblique view (FIG. 32C), the firstencapsulant 111 is constructed with multiple refractive index layers incup-stacking style and the second encapsulant 121 is constructed withmultiple refractive index layers in Babel Tower style. Also, themulti-layer construction has different refractive indices arranged in adecreasing fashion from proximal layers to distal layers.

As illustrated in FIG. 33A, the first encapsulant 111 has theconfigurations as microstructure 112 formed as the top surface of theuppermost layer. In addition, one interface of the first encapsulant 111with multiple refractive index layers may be configured as a curvaturelens 113. The microstructure 112 is embodied as a set of concentric arcsconcave toward the photodiode and the curvature lens 113 is embodied asa parabolic surface concave to the light source 110, while a photodiodeis sealed in the second encapsulant 121 without a microstructure. In thecross sectional view (FIG. 33B) and oblique view (FIG. 33C), the firstencapsulant 111 is constructed with multiple refractive index layers incup-stacking style and the second encapsulant 121 is constructed withmultiple refractive index layers in pancake stack style. Also, themulti-layer construction has different refractive indices arranged in adecreasing fashion from proximal layers to distal layers.

As illustrated in FIG. 34A, the first encapsulant 111 has theconfigurations as microstructure 112 formed as the top surface of theuppermost layer. In addition, one interface of the first encapsulant 111with multiple refractive index layers may be configured as a curvaturelens 113. The microstructure 112 is embodied as a set of concentric arcsconcave toward the photodiode and the curvature lens 113 is embodied asa parabolic surface concave to the light source 110, while a photodiodeis sealed in the second encapsulant 121 without a microstructure. In thecross sectional view (FIG. 34B) and oblique view (FIG. 34C), both thefirst encapsulant 111 and the second encapsulant 121 are separatelyconstructed with multiple refractive index layers in a cup-stackingstyle. Also, the multi-layer construction has different refractiveindices arranged in a decreasing fashion from proximal layers to distallayers.

As illustrated in FIG. 35A, a photodiode is sealed in the secondencapsulant 121 with a microstructure 122 formed as the top surface ofthe uppermost layer and the microstructure 122 is embodied as a set ofconcentric circles. In the cross sectional view (FIG. 35B) and obliqueview (FIG. 35C), the second encapsulant 121 is constructed with multiplerefractive index layers in Babel Tower style.

As illustrated in FIG. 36A, a photodiode is sealed in the secondencapsulant 121 with a microstructure 122 formed as the top surface ofthe uppermost layer and the microstructure 122 is embodied as a set ofconcentric circles. In the cross sectional view (FIG. 36B) and obliqueview (FIG. 36C), the second encapsulant 121 is constructed with multiplerefractive index layers in pancake stack style.

As illustrated in FIG. 37A, a photodiode is sealed in the secondencapsulant 121 with a microstructure 122 formed as the top surface ofthe uppermost layer and the microstructure 122 is embodied as a set ofconcentric circles. In the cross sectional view (FIG. 37B) and obliqueview (FIG. 37C), the second encapsulant 121 is constructed with multiplerefractive index layers in a cup-stacking style.

In one example as shown in FIG. 38A, a photodiode is sealed in thesecond encapsulant 121 with a microstructure 122 formed as the topsurface of the uppermost layer. In the example, the optical sensormodule comprises optical directional components 123 disposed between thetwo adjacent refractive index layers, wherein the optical directionalcomponents are curvature lenses. Further, two curvature lenses 123 areconfigured in the second encapsulant 121. In the cross sectional view(FIG. 38B) and oblique view (FIG. 38C), the first encapsulant 111 isconstructed with multiple refractive index layers in cup-stacking styleand the second encapsulant 121 is constructed of a stack of multiplelayers in Babel Tower style, where the curvature lenses 123 are embodiedas parabolic plane concave to the photodiode.

In one embodiment of the present disclosure, the optical sensor modules10 may further comprise a cover 150 distal to the first encapsulant 111and/or the second encapsulant 121. The cover 150 serves as a contactinterface between the object surface 190, such as a biological tissuesurface or a skin surface, to increase the durability of the opticalsensor module 10 and the consistency of measurement. As shown in FIG.39A, the optical sensor modules 10 may also comprise a cover 150 infront of the first encapsulant 111 and the second encapsulant 121, andthe cover 150 is located between the encapsulants and the object surface190. With a slight press, the cover 150 provide an increased contactarea with the object surface 190 to allow better optical reflection anddiffusion. The cover 150 may be integrated as a part of the opticalsensor module 10 or may be a part of the housing of the optical sensordevice.

In addition, the internal surface or the external surface of the cover150 may be coated with a thin film 151. The thin film 151 may be ananti-reflective or an anti-scratch thin film. As shown in FIG. 39B, thethin film 151 of external surface of the cover 150 is embodied as ananti-scratch thin film (such as polyethylene terephthalate, or siliconhard coating) and the one of the internal surface is embodied as ananti-reflective thin film.

The optical sensor modules 10 may also comprise a thin film 151 coveringan encapsulant. With thin film technology, the SNR of the optical sensormodule 10 may be further improved. The thin film 151 may be ananti-reflective thin film or a filter thin film. The anti-reflectivethin film may be an index-matching film (for example, Rayleigh film) oran interference film to improve light extraction efficiency by reducingFresnel reflection at the interface between different refractiveindices. The filter thin film may be a long-pass filter, a short-passfilter, or a band-pass filter to clear down the full width at halfmaximum (FWHM) of the emitting light or filter out the noise fromundesired wavelengths. Additionally, the anti-scratch thin film may beapplied to prevent the signal loss caused by scratches.

As shown in FIG. 40A, both the surfaces of the first encapsulant 111 andthe second encapsulant 121 are coated with a thin film 160. The thinfilm 160 of the first encapsulant 111 is embodied as an anti-reflectivethin film (FIG. 40B) and the thin film 160 of the first encapsulant 111is embodied as a band-pass filter thin film (FIG. 40C). Theanti-reflective thin film improves the light extraction efficiency andthe band-pass filter thin film reduces noise. It is contemplated thatthe thin film 160 of the first encapsulant 111 is embodied as aband-pass filter thin film and the thin film 160 of the firstencapsulant 111 is embodied as an anti-reflective thin film, so that theFWHM of the emitting light has a clear cut-off wavelength and thephotodiode detects the filtered signals within a specific window. In theapplication of the fluorescence detection long-pass filter thin filmmaybe applied to the second encapsulant 121 to acquire a clearfluorescent signal avoiding the excitation light. Also, the opticalsensor module 10 may further comprise a cover 150 in front of the firstencapsulant 111 and the second encapsulant 121. As shown in FIG. 41A,the optical sensor module 10 further comprises a cover 150 and the thinfilms 160 covering the encapsulants (FIGS. 41B and C).

Furthermore, the optical sensor module 10 may further comprise both acover 150 coated with thin film 151 and the thin films 160 covering theencapsulants (FIG. 42A). As shown in FIG. 42B, the thin film 151 ofexternal surface of the cover 150 is embodied as an anti-scratch thinfilm (such as polyethylene terephthalate, or silicon hard coating) andthe one of the internal surface is embodied as an anti-reflective thinfilm. The thin film 160 of the first encapsulant 111 is embodied as ananti-reflective thin film (FIG. 42C) and the thin film 160 of the firstencapsulant 111 is embodied as a band-pass filter thin film (FIG. 42D).

The optical sensor module 10 may have an optical directional componenton the medial surface of the first encapsulant 111 or on the medialsurface of the second encapsulant 121. The optical directional componentmay have an inclined plane or a curvature lens or the combinationthereof. An inclined plane may have an inclined angle 315 between thesurface of the encapsulant and the plane of the substrate. The inclinedangle may be around ninety degrees to twenty degrees. In addition, acurvature lens may be configured in combination of an inclined plane. Inone example, the curvature lens may have a radius of curvature with 0.6millimeter and the inclined angle is about forty degrees when thepartition has a height of 0.4 millimeter. Therefore, light emitted fromthe light source is more concentrated above the partition locatedbetween the light source and the photodetector, and less shed onto thepartition 130.

As illustrated in FIG. 43A, the medial surface of the first encapsulant111 is configured as an optical directional component 113, and theoptical directional component 113 is embodied as an inclined plane,while the photodetector 120 is sealed in the second encapsulant 121 withan inclined plane with a larger inclined angle. In the cross sectionalview (FIG. 43B) and oblique view (FIG. 43C), both the first encapsulant111 and the second encapsulant 121 are separately constructed intrapezoid shape. The optical directional component 113 of the medialsurface of the first encapsulant 111 has an inclined angle smaller thanthe inclined angle of the second optical directional component 123.

As illustrated in FIG. 44A, the medial surface of the first encapsulant111 is configured as an optical directional component 113, and theoptical directional component is embodied as an inclined plane.Additionally, the photodetector 120 is sealed in the second encapsulant121 with an optical directional component 123 as an inclined plane. Inthe cross sectional view (FIG. 44B) and oblique view (FIG. 44C), boththe first encapsulant 111 and the second encapsulant 121 are separatelyconstructed in trapezoid shape. The first encapsulant 111 and the secondencapsulant 121 has an inclined plane with an inclined angle tofacilitate light extraction efficiency and light receiving efficiency,respectively. The inclined angle of the first optical directionalcomponent 113 may be different from the inclined angle of the secondoptical directional component 123.

As illustrated in FIG. 45A-C, the medial surface of the firstencapsulant 111 is configured as an optical directional component 113,and the optical directional component 113 is embodied as a curvatureplane. Additionally, the photodetector 120 is sealed in the secondencapsulant 121 with an optical directional component 123, which isembodied as a curvature plane. In the cross sectional view (FIG. 45B)and oblique view (FIG. 45C), both the first encapsulant 111 and thesecond encapsulant 121 are separately configured with a curvature planeon the medial surface. It is contemplated that the optical directionalcomponent of the second encapsulant 121 may differ from the one of thefirst encapsulant 111. For example, the first encapsulant may have acurvature plane on the medial surface, while the second encapsulant hasan inclined plane.

FIGS. 46-48 shows the situation of measuring the reflected light from anobject surface 190 by the optical sensor module 10 with opticaldirectional components, but other optical sensor modules within thepresent disclosure is also suitable for the application. The objectsurface 190 may be a surface of a biological tissue, such as skin ormucosa. The optical sensor module 10 is tolerable to various workingconditions, such as rough object surface and relative motion between thesensor module and object surface. In FIGS. 46A and 46B, the top surfaceof the optical sensor module 10 may directly contact with the objectsurface 190. In FIGS. 47A and 47B, the upper side of the optical sensormodule 10 may have a limited distance from the object surface 190 butthe optical sensor module 10 is still capable of acquiring sufficienteffective signals. In FIGS. 48A and 48B, a cover 150 may directly attachthe object surface 190, and the optical sensor module 10 have a limiteddistance from the cover 150. The cover 150 may be a part of opticalsensor module 10 or be integrated with a housing of an optical sensingaccessory or an optical sensing device. The material of the cover may beselected from organic glass, such as PMMA or PC, or inorganic glass suchas silicate glass or silicone compound. In addition, the internalsurface or the external surface of the cover 150 may be coated with athin film. The thin film may be an anti-reflective (such asindex-matching thin film or interference thin film) or an anti-scratchthin film (such as polyethylene terephthalate, or silicon hard coating).Furthermore, the optical sensor module 10 may further comprise a thinfilm covering an encapsulant. With thin film technology, the SNR of theoptical signals may be further improved. The thin film may be ananti-reflective thin film or a filter thin film. The anti-reflectivethin film may be an index-matching film (for example, Rayleigh film) oran interference film to improve light extraction efficiency by reducingFresnel reflection at the interface between the encapsulants and theenvironmental medium. The filter thin film may be a long-pass filter, ashort-pass filter, or a band-pass filter to clear down the full width athalf maximum (FWHM) of the emitting light or filter out the noise fromundesired wavelengths.

Furthermore, a cover 150 may be coupled to the partition 130 and thepackaging wall 131 enclosing the first encapsulant 111 and the secondencapsulant 121. The cover may have surface configurations, such as amicrostructure, a curvature lens, or the combination thereof. The covermay have tight connection to the packaging wall 131 to have goodprotection from ambient moisture, water, or dusts.

In FIG. 49A-C, the cover 150 is configured with a planar surface with amicrostructure on the inner surface of the cover 150. In FIG. 49A, thecover comprises two optical transparent windows 152 and each window islocated beyond the first encapsulant 111 or the second encapsulant 121.In FIGS. 49B and 49C, the cover comprises two microstructures on theinner surface of the optical transparent windows 152.

In FIG. 50A-C, the cover 150 is configured with a curvature lens on thesurface of the cover 150. In FIG. 50A, the cover comprises twosemicircular optical transparent windows 152 and each window is locatedbeyond the first encapsulant 111 or the second encapsulant 121. In FIGS.50B and 50C, the cover 150 comprises two plano-convex lens on thesurface of the optical transparent windows.

In FIG. 51A-C, the cover 150 is configured with a curvature lens on theouter surface of the cover 150 and a microstructure on the inner surfaceof the cover 150. In FIG. 51A, the cover comprises two semicircularoptical transparent windows 152 and each window is located beyond thefirst encapsulant 111 or the second encapsulant 121. In FIGS. 51B and51C, each optical transparent window has a plano-convex lens on theouter surface and a microstructure on the inner surface.

In FIG. 52A-C, the cover 150 is configured with a curvature lens on thesurface of the cover 150. In FIG. 52A, the cover comprises two opticaltransparent windows 152 and each window is located beyond the firstencapsulant 111 or the second encapsulant 121. In FIGS. 52B and 52C, theoptical transparent window on the light source side has a plano-convexlens and the optical transparent window on the light source side has aplano-concave lens.

In FIG. 53A-C, the cover 150 is configured with a curvature lens on theouter surface of the cover 150 and a microstructure on the inner surfaceof the cover 150. In FIG. 53A, the cover comprises two opticaltransparent windows 152 and each window is located beyond the firstencapsulant 111 or the second encapsulant 121. In FIGS. 53B and 53C, theoptical transparent window on the light source side has a plano-convexlens and the optical transparent window on the light source side has aplano-concave lens. Both the plano-convex lens and the plano-concavelens further comprise microstructures on the inner surface of the cover150.

In FIG. 54A-C, the cover 150 is configured with a curvature lens on thesurface of the cover 150. In FIG. 54A, the cover 150 comprises twooptical transparent windows 152 and each window is located beyond thefirst encapsulant 111 or the second encapsulant 121. In FIGS. 54B and54C, each of the optical transparent windows has a meniscus lens.

An optical sensor module may further comprise a microcontroller, ananalogue front end, an operational amplifier, a light source driver orthe combination thereof. A microcontroller is an integrated circuit chipconfigured to trigger the emittance of the light sources or to processthe signals received from the photodetectors. An analogue front end isconfigured to receive and process the analogue signals from thephotodetectors. The microcontroller and analogue front end may have afunction of analogue to digital signal conversion. An operationalamplifier is configured to receive and process the analogue signals fromthe photodetectors. An operational amplifier can amplify at least a partof the signals to achieve signal augmentation, filtering, or noisereduction. A light source driver is configured to control the electricalcurrent flow through the light source, such as LED or laser diode. Theelectrical connections between an analogue front end, a microcontroller,an operational amplifier, a light source driver, the light source andthe photodetectors may be coupled through the circuit printed within thesubstrate.

In FIG. 55A-C, an optical sensor module has an analogue front end 141between the encapsulants and the substrate to receive the signals from aphotodetector 120. The analogue front end can be integrated as a part ofthe substrate 140 and have electrical connection to the photodetector120. In FIGS. 56A and 56B, an optical sensor module has an analoguefront end 141 beside the encapsulants separated by the packaging walls.

In FIGS. 57A and 57B, an optical sensor have two light sources 110, aphotodetector 120, a partition 130, the packaging walls 131, amicrocontroller 142 and an analogue front end 141 beside theencapsulants separated by the packaging walls 131. The microcontroller142 and the analogue front end 141 may have electrical connections toeach other and to the photodetectors 120.

In FIGS. 58A and 58B an optical sensor module have a light source 110,four photodetectors 120, a partition 130, a microcontroller 142 and ananalogue front end 141. A microcontroller 142 and an analogue front end141 are separately located between the two second encapsulants 121 andbeside the partition 130. The analogue front end may have electricalconnections to the photodetectors 120 and the microcontroller 142 haselectrical connections of the analogue front end 141 to receive thesignals processed by the analogue front end 141 from the photodetectors120. In FIGS. 59A and 59B sensor have a light source 110, fourphotodetectors 120, a partition 130, a microcontroller 142 and threeanalogue front ends 141. The microcontroller 142 and the three analoguefront ends 141 are separately located between the two secondencapsulants 121 and beside the partition 130.

In FIGS. 60A and 60B an optical sensor module has a light source 110,four photodetectors 120, a partition 130, a microcontroller 142, anoperational amplifier 143 and a light source driver 144. Themicrocontroller 142, the operational amplifier 143 and the light sourcedriver are separately located between the two second encapsulants 121and beside the partition 130. The light source driver 144 is connectedto the light source 110 to control the emitting frequency, duration, orintensity. The operational amplifier may have electrical connections tothe photodetectors to augment the photocurrent and the microcontrollerconnects to the operational amplifier to receive the signals processedby the operational amplifier.

An optical sensor module 10 may be a multi-directional optical sensormodule 5. In some examples, the multi-directional optical sensor module5 is a bi-directional sensor module 5. The bi-directional optical sensormodule 5 is manufactured to emit light and detect the reflected lightfrom two directions, and the received reflected light will beproportionally transduced into electrical current. Bi-directional sensormodule 5 comprises a light source 110, a first encapsulant 111 over thelight source 110, two photodetectors 120, wherein all mentioned aboveare mounted on a substrate 140. Each photodetector 120 is covered by asecond encapsulant 121 and both second encapsulants 121 are covered bythe first encapsulant 111. The bi-directional optical sensor module 5may be fabricated in a single compact package. Using the twophotodetectors 120, the bi-directional optical sensor module 5 maydetect light from different parts of body for various applications. Itis also contemplated that the bi-directional optical sensor module 5 mayemploy a discrete light source 110 and a photodetector 120 that areseparately packaged and mounted to one or more printed circuit boards(also referred to as “PCB”) depending on various design requirements. Inaddition, the light source may comprise an array of LEDs or a pluralityof LEDs, while each photodetector may comprise an array of photodiodesor a plurality of photodiodes.

The construction of the encapsulants features a light splitting andlight extraction design for the first encapsulant 111 and a lightcollection design for the second encapsulants 121. The first encapsulant111 and the second encapsulants 121 may have the refractive indexmediating the optoelectronics and the environment. There are two secondencapsulants 121 located on the two sides of the light source 110. Morespecifically, the first encapsulant 111 has a predetermined shape forsplitting the light from the light source 110 into two beams of light indifferent directions and for guiding them to the object surface undertest; the first encapsulant 111 seals the light source 110 and alsocovers the two second encapsulants 121 sealing the photodetectors 120.The first encapsulant 111 may take advantage of total internalreflection of the emitted light by a difference in the refractive indexor a predetermined curvature, or the first encapsulant 111 may becovered with the reflective coating 180 confining the emitted light.Each of the second encapsulants 121 may have a predetermined shape forcollecting the light reflected from the objects. For example, the secondencapsulants are substantially prismatic or quadri spherical.Furthermore, the two second encapsulants 121 may be engineered as asymmetric or an asymmetric shape, and also the first encapsulant 111 mayhave various shapes for specific requirements. For example, the topsurface of the first encapsulant 111 may be two inclined planesintersecting substantially above the light source 110 or may be twocurved plane intersecting substantially above the light source 110.

A coating may be disposed on different surfaces of the encapsulants forblocking the stray light directly from the light source 110 to thephotodetector 120 or guiding/collecting the light to/from the objects.The coating may be a thin film of metal or a reflective material (forexample Ag or TiO2 riched compound).

The contact surfaces 191 (one example as shown in FIG. 61B) are theopenings for the emitted (the first encapsulant 111) and reflected (thesecond encapsulant 121) light and are used to attach the objects, whilethe side surfaces are the surface shown in the cross sectional view andthe contralateral surface. At least part of the contact surface of theencapsulants may be formed as a microstructure. For example, the firstencapsulant 111 includes a microstructure 112 formed as the contactsurface of the first encapsulant 111. The encapsulant 111 withmicrostructure(s) enhances the signal strength because the light isconcentrated toward intended direction from the light source 110 towardthe photodetector 120, while the light passes through the microstructure122 of the encapsulant 121.

A wall may be also be disposed on the side surfaces, of the encapsulantsfor blocking the stray light formed of opaque material, which blocks viareflection and/or absorption in the specific spectrum of wavelengthsemitted by the light source 110, for noise reduction.

The bi-directional optical sensor module 5 is a compact packaged modulecomprising of a light source 110, a photodetector 120, a first and twosecond encapsulants 121, and a substrate 140. The primary goal of thepresent technology is to be capable of measuring two directions of thereflected optical signals by specific shapes of the encapsulants. Theseshapes also improve the performance of the bi-directional optical sensormodule 5 achieved by enhancing the light extraction efficiency,directing the light path, or reducing the stray light. Othermodification and further application without departing the scope ofdisclosure are presented in the embodiments. It may be embodied as thesimple composition with one light emitting diode (LED) and two siliconphotodiodes all mounted on a printed circuit board as a substrate 140.Both LED and silicon photodiode are hermetically sealed, separately,with epoxy encapsulants. In the example for measuring oxygenation ofbiological tissue, both wavelengths in infrared and red regions arerequired. Therefore, one red LED and one infrared LED may be mounted onthe same sensor module 5. In other implementations that are within thescope of the present disclosure, the number and the arrangement of thelight sources 110 and photodetectors 120 may be modified.

As shown in FIG. 61-69, the general construction of the bi-directionaloptical sensor module 5 is presented. The bi-directional optical sensormodule 5 comprises two LEDs and two silicon photodiodes, wherein bothare mounted on a substrate 140. The first encapsulant 111 covers thelight source 110, while the two second encapsulants 121 cover the twophotodiodes 120. In the embodiments, an encapsulant may havemodifications in configuration and construction. For example, theconfiguration of the first encapsulant 111 may be trapezoid shape orcylindrical shape. In addition, the contact surfaces of the firstencapsulant 111 are configured with a first microstructure 112, and thecontact surfaces of the second encapsulants 121 may have a secondmicrostructure 122.

In the examples of the present disclosure, as shown in FIGS. 61-68, asecond coating 181 is disposed on the top surface of the secondencapsulants 121 to reduce light leakage directly from the light sourceto the photodetector and reduce the effect of ambient stray light. InFIGS. 61-65, the first coating 180 is disposed on the surface of thefirst encapsulant 111 to limit light leakage and thus enhance the lightemitting toward the contact surfaces. The surface of both encapsulantshave a predetermined surface configuration to enhance SNR. For examplein FIG. 61B, the top surface of the first encapsulant may be formed astwo inclined plane 111 a, 111 b intersecting at around the above of thelight source 110 and formed as an intersected line 111 c as shown inFIG. 61A. In the examples, each of the inclined planes is about parallelto the surface plane of the second encapsulant on the same side. In someexamples, the inclined planes 111 a, 111 b may have asymmetric shape orsize, and may have cylindrical shape. For ease of presentation, thefirst coating 180 is disposed on the top surface of the firstencapsulant 111, and the second coating 181 is the disposed on the topsurface of the second encapsulant 121. Further, the first encapsulant111 has refractive index, n₁ and the two second 121 encapsulants haverefractive indices, n₂, wherein n₁ and n₂ may be different.

The top surfaces of the first encapsulant 111 and the two secondencapsulants 121 have a predetermined tilting angle or curvature;therefore, more emitted light is extracted from the LEDs and morereflected light is collected to the photodiodes to enhance effectivesignal strength.

As illustrated in the top view (FIG. 61A), the substrate 140 area isdivided into three regions by two straight lines; one rectangular areaenclosing the LEDs and two rectangular areas, on the two sides of theLEDs, enclosing the two photodiodes. In the cross sectional view (FIG.61B) and the oblique view (FIG. 61C), the two second encapsulants 121are embodied as a shape of a triangle prism, horizontally disposed ontwo rectangular areas respectively and sealing the two photodiodes.Additionally, the first encapsulant 111 is embodied as a shape of twoside-by-side trapezoid prisms, and horizontally disposed on two secondencapsulants 121 and sealing the LEDs. In addition, there is the firstcoating 180 on the first encapsulant 111 and the second coating 181 onthe second encapsulants 121. The two second encapsulants 121 areconstructed together or separately with their top surfaces are coveredby the second coating 181; then the first encapsulant 111 areconstructed on top of the two second encapsulants 121 with its topsurface is covered by the first coating 180.

In the top view (FIG. 62A) and the cross sectional view (FIG. 62B), thetwo second encapsulants 121 are embodied as a shape of a triangle prism,horizontally disposed on two rectangular areas respectively and sealingthe two photodiodes. Additionally, the first encapsulant 111 is embodiedas a shape of two side-by-side trapezoid prisms, and horizontallydisposed on two second encapsulants 121 and sealing the LEDs. It iscontemplated that the contact surfaces of the first 111 and second 121encapsulants may be formed as different microstructures (for example,DOEs or Fresnel patterns as shown in FIGS. 62C and 62D) to enhance thelight extraction/receiving efficiency. For example, the firstmicrostructures are configured in a set of concentric arcs with widerintervals than the second microstructures.

In the top view (FIG. 63A) and the cross sectional view (FIG. 63B), thetwo second encapsulants 121 are embodied as a shape of a triangle prism,horizontally disposed on two rectangular areas respectively and sealingthe two photodiodes. Additionally, the first encapsulant 111 is embodiedas a shape of two asymmetric side-by-side trapezoid prisms, andhorizontally disposed on two second encapsulants 121 and sealing theLEDs. It is also contemplated that the configuration (for example theinclined angle of top surfaces) and the material (for example refractiveindex) of the two second encapsulants 121 and the coatings 181 maydiffer from each other. In FIG. 63B, the distance between the lightsource 110 to the contact surface, d1, is shorter than the distancebetween the light source 110 to the opposite contact surface, d2. Thetwo tilting angles, θ1 and θ2, of the top surface of the firstencapsulant may be different. For example, asymmetric secondencapsulants 121 resulting in an asymmetric first encapsulant 111. Inaddition, the contact surfaces of the first 111 and second 121encapsulants may be formed as different microstructures (for example,DOEs or Fresnel patterns as shown in FIGS. 63C and 63D) to enhance thelight extraction/receiving efficiency.

As illustrated in the top view (FIG. 64A), the substrate 140 area mayalso be divided into three regions in a different way by two curves; thetwo rectangular areas may be replaced by two semi-circles enclosing thetwo photodiodes as shown in this embodiment, while the rest area of thesubstrate 140 enclosing the LEDs. In the cross sectional view (FIG. 64B)and the oblique view (FIG. 64C), the two second encapsulants 121 areembodied as a shape of a quarter-sphere, disposed on two semi-circularareas respectively and sealing the two photodiodes. Additionally, thefirst encapsulant 111 is embodied as a shape of two side-by-sidetrapezoid prisms, horizontally disposed on two second encapsulants 121,and seals the LEDs. In addition, there is the first coating 180 on thefirst encapsulant 111 and the second coating 181 on the secondencapsulants 121. The two second encapsulants 121 may also beconstructed as a shape of a quarter-ellipsoid, a partial parabolicsphere or the like with their top surfaces covered by the second coating181; the first encapsulant 111 are constructed on top of the two secondencapsulants 121 with the top surface covered by the first coating 180.

As illustrated in the top view (FIG. 65A), the substrate 140 area mayalso be divided into three regions in a different way by two curves; thetwo rectangular areas may be replaced by two semi-circles enclosing thetwo photodiodes as shown in this embodiment, while the rest area of thesubstrate 140 enclosing the LEDs. In the cross sectional view (FIG.65B), the two second encapsulants 121 are embodied as a shape of aquarter-sphere, disposed on two semi-circular areas respectively andsealing the two photodiodes. It is contemplated that the contactsurfaces of the first 111 and second 121 encapsulants may be formed asdifferent microstructures (for example, DOEs or Fresnel patterns asshown in FIGS. 65C- and 65D) to enhance the light extraction/receivingefficiency.

In the present disclosure, as shown in FIGS. 66-68, the firstencapsulant is formed as a shape of side-by-side cylinders to enhancethe light extraction efficiency. The top surface of the firstencapsulant 111 may be configured as two curvature intersecting beyondthe light source 110. The curvature design of the first encapsulant 111may follow the rule of the total internal reflection at a critical angle(θ_(c)=arcsin(n₁/n₀)), where the refractive index of the firstencapsulant, n₁, is larger than the environment surrounding (for exampleair) the optical sensor module, n₀. Further, the first 111 and the twosecond 121 encapsulants may have different refractive indices, n₁ andn₂. As a result, the interface between the first encapsulant and one ofthe second encapsulants follows the rule of the total internalreflection at a critical angle (θ_(c)=arcsin(n₁/n₂)) to reduce lightleakage directly from the light source to the photodetector.

The outer surfaces of the first encapsulant 111 and the two secondencapsulants 121 may have modifications of configuration. For example,each top surface of the two second encapsulants may be an inclined planewith a predetermined angle between the top surface and the substrate. Inone example, each top surface of the two second encapsulants may be acurvature concaved toward the photodetector on the same side. As aresult, more emitted light is extracted from the LEDs and more reflectedlight is collected to the photodiodes to enhance effective signalstrength.

As illustrated in the top view (FIG. 66A), the substrate area is dividedinto three regions by two straight lines; one rectangular area enclosingthe LEDs and two rectangular areas, on the two sides of the LEDs,enclosing the two photodiodes. In the cross sectional view (FIG. 66B)and the oblique view (FIG. 66C), the two second encapsulants 121 areembodied as a shape of a triangle prism, horizontally disposed on tworectangular areas respectively and sealing the two photodiodes.Additionally, the first encapsulant 111 is embodied as a shape of twoside-by-side quarter-cylinder as shown in this embodiment andhorizontally disposed on two second encapsulants 121 and sealing theLEDs. In addition, there is the first coating 180 on the firstencapsulant 111 and the second coating 181 on the second encapsulants121. The two second encapsulants 121 are constructed together orseparately with their top surfaces are covered by the second coating181; then the first encapsulant 111 may also be constructed as twocurved surfaces on top of the two second encapsulants 121.

As illustrated in the top view (FIG. 67A), the substrate area may alsobe divided into three regions in a different way by two curves; the tworectangular areas may be replaced by two semi-circles enclosing the twophotodiodes as shown in this embodiment, while the rest area of thesubstrate 140 enclosing the LEDs. In the cross sectional view (FIG. 67B)and the oblique view (FIG. 67C), the two second encapsulants 121 areembodied as a shape of a triangle prism, horizontally disposed on tworectangular areas respectively and sealing the two photodiodes.Additionally, the first encapsulant 111 is embodied as a shape of twoside-by-side quarter-cylinder as shown in this embodiment andhorizontally disposed on two second encapsulants 121 and sealing theLEDs. In addition, there is the first coating 180 on the firstencapsulant 111 and the second coating 181 on the second encapsulants121. The two second encapsulants 121 may also be constructed as a shapeof a quadrispherical, a quarter-ellipsoid or a partial parabolic sphereor the like with their top surfaces are covered by the second coating181; then, the first encapsulant 111 may also be constructed as twocurved surfaces on top of the two second encapsulants 121.

As illustrated in the top view (FIG. 68A), the substrate area may alsobe divided into three regions in a different way by two curves; the tworectangular areas may be replaced by two semi-circles enclosing the twophotodiodes as shown in this embodiment, while the rest area of thesubstrate 140 enclosing the LEDs. In the cross sectional view (FIG.68B), the two second encapsulants 121 are embodied as a shape of atriangle prism, horizontally disposed on two rectangular areasrespectively and sealing the two photodiodes. It is contemplated thatthe contact surfaces of the first 111 and second encapsulants 121 may beformed as different microstructures (for example, DOEs or Fresnelpatterns as shown in FIGS. 68C and 68D) to enhance the lightextraction/receiving efficiency. In addition, a coating 180 or a wall(nontransparent sealing material) may be disposed on the top surfaces ofthe second encapsulants to enhance SNR.

In one example of the present disclosure, as shown in FIG. 69, the firstencapsulant 111 and the two second 121 encapsulants may have differentrefractive indices, where the refractive index of the secondencapsulants 121, n₂, is larger than the one of the first encapsulant111, n₁, to reduce direct light leakage from the light source to thephotodetectors and ambient stray light according to the Fresnel rule.The surface of both encapsulants have a predetermined surfaceconfiguration to enhance SNR; in this embodiment, the first encapsulant111 is formed as a shape of side-by-side cylinders to enhance the lightextraction efficiency. The curvature design of the first encapsulant 111may follow the rule of the total internal reflection at a critical angle(θ_(c)=arcsin(n₁/n₀)), where the refractive index of the firstencapsulant 111, n₁, is larger than the environment surrounding (e.g.air) the optical sensor module, n₀.

The surface planes of the first encapsulant 111 and the two secondencapsulants 121 have a predetermined tilting angle or curvature, andhence the second coating 181; therefore, more emitted light is extractedfrom the LEDs and more reflected light is collected to the photodiodesto enhance effective signal strength.

As illustrated in the top view (FIG. 69A), the substrate 140 area mayalso be divided into three regions in a different way by two curves; thetwo rectangular areas may be replaced by two semi-circles enclosing thetwo photodiodes as shown in this embodiment, while the rest area of thesubstrate 140 enclosing the LEDs. In the cross sectional view (FIG. 69B)and the oblique view (FIG. 69C), the two second encapsulants 121 areeach embodied as a shape of a triangle prism, horizontally disposed ontwo rectangular areas respectively and sealing the two photodiodes.Additionally, the first encapsulant 111 is embodied as a shape of twoside-by-side quarter-cylinder as shown in this embodiment andhorizontally disposed on two second encapsulants 121 and sealing theLEDs. In addition, there is the first coating 180 on the firstencapsulant 111 and the second coating 181 on the second encapsulants121. The two second encapsulants 121 may also be constructed as a shapeof quadrispherical, a quarter-ellipsoid or a partial parabolic sphere orthe like; then the first encapsulant 111 may also be constructed as twocurved surfaces on top of the two second encapsulants 121.

It is also contemplated that the configuration (for example, inclinedangle of top surfaces) and the material (for example, refractive index)of the two second encapsulant 121/coating 180 may differ from eachother. The second encapsulants 121 may be asymmetric resulting anasymmetric first encapsulant 111, for more specific applications.Further, the side surfaces of the first 111 and second 121 encapsulantsmay be formed as different microstructures to enhance the lightextraction/receiving efficiency.

An optical sensor module 10 may be a dual sensor module 6. The dualsensor module 6 is manufactured to detect the reflected light andelectric signals. The dual sensor module comprises a light source, afirst encapsulant over the light source, a photodetector, a secondencapsulant over the photodetector, a packaging wall, a detector circuitboard, and at least one electrode.

An electrode is configured to be a transducer or to detect an externalcircuit formed by the contact with an object surface. An electrode is anelectrically conductive material, which connects between the externalcircuit and the detector circuit board inside the dual sensor module.The material of electrodes are usually metal or alloy with goodconductivity, for example, copper or gold. Moreover, a single electrodemay serve as a thermocouple, made of two pieces of alloy with adifferent Seeback coefficient (for example, alumel and chromel). Theelectrodes are arranged to have an adequate contact interface with theobject surface (for example, biological tissue or skin surface).

A part of a substrate 140 may be configured as a detector circuit board175. A detector circuit board 175 is configured to have an electricalconnection to at least an electrode 170 and to provide electrical pin(s)for further signal delivery. The detector circuit board 175 may comprisea logic circuit or an operational amplifier circuit to help theelectrodes 170 to obtain the electrical properties, such as electricalcurrent, conductance, impedance, or electrical potential difference. Thedetector circuit board 175 may be integrated with the substrate havingthe optoelectronics thereon or may be a separate printed circuit boardconnected to the substrate. In some examples as shown in FIG. 73B andFIG. 74B, the substrate has the first part 140 of the substrateconfigured to provide connection to the light source 110 and thephotodetector 120 and the second part 175 of the substrate configured asa detector circuit board to provide electrical connection to theelectrodes 170.

The dual sensor module 6 is an integrated sensor module comprising anoptical sensor part and an electrical sensor part to have multiplefunction within a single piece of a dual sensor module 6. The dualsensor module 6 has many advantages, such as volume miniaturization andin situ dual signal acquisition. The single electrode 170 in a dualsensor module may be solely functional as a thermocouple. The singleelectrode 170 in a dual sensor module may be cooperated with anotherdual sensor module or an independent electrode to form as a functionalpair of electrodes. In FIG. 70A, the dual sensor module has the lightsource 110, the first encapsulant 111 covering the light source 110, thephotodetector 120, the second encapsulant 121 covering the photodetector120, the packaging wall 131, the substrate 140 and the electrode 170disposed between the light source 110 and the photodetector 120. In FIG.70B, the light source 110, the photodetector 120 and the electrode 170are disposed on the same substrate 140.

As shown in FIG. 71A, the dual sensor module has the light source 110,the first encapsulant 111 covering the light source 110, thephotodetector 120, the second encapsulant 121 covering the photodetector120, the packaging wall 131, the detector circuit board 175 and theelectrodes 170. The packaging wall 131 is disposed between the lightsource 110 and the photodetector 120. The two electrodes 170 aredisposed on the opposite border of the detector circuit board 175. Oneelectrode 170 is disposed laterally to the light source 110 and theother electrode 170 is disposed laterally to the photodetector 120. Thepackaging wall 131 is configured to reduce the direct light leakage fromthe light source 110 and the photodetector 120 and may extendbilaterally to further block ambient light. In FIG. 71B, the lightsource 110, the photodetector 120 and the electrode 170 are disposed onthe same detector circuit board 175.

As shown in FIG. 72A, the dual sensor module has the light source 110,the first encapsulant 111 covering the light source 110, thephotodetector 120, the second encapsulant 121 covering the photodetector120, the packaging wall 131, the detector circuit board 175 and theelectrodes 170. One electrode is disposed between the light source 110and the photodetector 120 and the other electrode is disposed on theborder of the detector circuit board. The packaging wall 131 isconfigured to block ambient light and to separate the two electrodes.The packaging wall 131 is electrically insulated, so that the twoelectrode are capable of detecting the electrical potential difference.In FIG. 72B, the light source 110, the photodetector 120 and theelectrodes 170 are disposed on the same detector circuit board 175. Itis contemplated that the electrodes 170 may be disposed on other sidesof the detector circuit board 175. For example, one electrode 170 isdisposed between the light source 110 and the photodetector 120, and theother electrode 170 is disposed on the border of the light source sideof the detector circuit board 175. For example, the dual sensor modulemay have a packaging wall 131 disposed between the light source 110 andthe photodetector 120 and the electrodes may be disposed perpendicularto the packaging wall 131.

As shown in FIGS. 73-74, the substrate 140 is composed by a first partand a second part. The first part of the substrate may have a lightsource 110 and the photodetector 120 thereon, while the second part ofthe substrate may be a detector circuit board 175 to provide connectionto the electrode(s) 170. The light source 110 and the photodetector 120are disposed on the substrate 140. The detector circuit board 175 may bemechanical connected to the substrate 140, or may be electricalconnected to the circuit within the substrate 140 for bettersynchronization between the optical measurement and the electricalmeasurement.

In FIG. 73A, the detector circuit board 175 is larger than the substrate140 and the substrate 140 and the two electrodes 170 are disposed on thedetector circuit board 175. The packaging wall 131 is disposed betweenthe light source 110 and the photodetector 120 to reduce light leakageand may extend to enclose the border of the substrate 140 to furtherblock ambient light. In FIG. 73B, each of the electrodes 170 haselectrical connection to the detector circuit board 175. The electrodesare separated from each other by the substrate 140. In FIG. 74A, twoelectrodes 170 are disposed on the detector circuit board 175 with alimited distance and thus may have a smaller impedance of the externalcircuit when being applied to an object surface. In FIG. 74B, each ofthe electrodes 170 has electrical connection to the detector circuitboard 175.

In FIGS. 75-79, the dual sensor module 6 may further comprise a cover150, and the cover 150 may be located, during application, between theencapsulants and the object surface, while not blocking the contactbetween the electrodes 170 and the object surface. The cover 150 servesas a contact interface between the object surface (such as a biologicaltissue surface or a skin surface) to increase the durability of the dualsensor module 6 and the consistency of measurement.

In one embodiment as shown in FIG. 75A, the dual sensor module 6comprises a cover 150 disposed beyond the light source 110 and thephotodetector 120, while at least a part of the electrode 170 isexposing outward. The cover 150 may be separated by the electrode 170 ormay be a single piece with a slot for exposure of the electrode 170. InFIG. 75B, the cover 150 may be mechanically connected to the packagingwall 131 to provide mechanical support.

In FIG. 76A, the cover 150 may be disposed beyond the light source 110and the photodetector 120, while at least a part of the two electrodes170 are exposed outward from the cover 150. In FIG. 76B, a packagingwall 131 is disposed between the light source 110 and the photodetector120 and provide mechanical support to the cover 150. The packaging wall131 may extend to enclose the border of the detector circuit board 175to block ambient light and provide better mechanical support for thecover 150.

In FIG. 77A, the cover 150 may be disposed beyond the light source 110and the photodetector 120, while at least a part of the two electrodes170 are exposed outward from the cover 150. The cover 150 may be asingle piece with one slot for exposure of the electrode 170 between thelight source 110 and the photodetector 120. The cover 150 may be asingle piece with two slots each for an electrode 170. The cover 150 maycomprise two separate parts for exposure of the electrodes 170. In FIG.77B, a packaging wall 131 is disposed to provide mechanical support tothe cover 150. The packaging wall 131 may extend to enclose the borderof the detector circuit board 175 to block ambient light and providebetter mechanical support for the cover 150. The packaging wall may beseparated by the electrodes 170 or may be fabricated as a continuouswall enclosing the border the detector circuit board 175.

In addition, the internal surface or the external surface of the cover150 may be coated with a thin film 151. The thin film may be ananti-reflective (such as index-matching thin film or interference thinfilm) or an anti-scratch thin film (such as polyethylene terephthalate,or silicon hard coating). As shown in FIG. 78A, both internal surfaceand the external surface of the cover 150 are coated with thin films. Inan enlarged view (FIG. 78B), the external surface of cover 150 iscovered with an anti-scratch thin film and the internal surface of thecover 150 is covered with an anti-reflective thin film. It iscontemplated that the two surfaces may be covered with same kind of thinfilm or one of the surfaces of the cover 150 may have no thin film.

In one example as shown in FIGS. 79A-C, the dual sensor module 6 mayfurther comprise a thin film 160 covering an encapsulant. With thin filmtechnology, the SNR of the optical signals may be further improved. Thethin film 160 may be an anti-reflective thin film or a filter thin film.The anti-reflective thin film may be an index-matching film (forexample, Rayleigh film) or an interference film to improve lightextraction efficiency by reducing Fresnel reflection at the interfacebetween the encapsulants and the environmental medium. The filter thinfilm may be a long-pass filter, a short-pass filter, or a band-passfilter to clear down the full width at half maximum (FWHM) of theemitting light or filter out the noise from undesired wavelengths.

As shown in FIG. 79A, both the surfaces of the first encapsulant 111 andthe second encapsulant 121 are coated with a thin film 160. The thinfilm 160 of the first encapsulant 111 is embodied as an anti-reflectivethin film (FIG. 79B) and the thin film 160 of the second encapsulant 121is embodied as a band-pass filter thin film (FIG. 79C). Theanti-reflective thin film improves the light extraction efficiency andthe band-pass filter thin film reduces noise. It is contemplated thatthe thin film 160 of the first encapsulant 111 may be a band-pass filterthin film and the thin film 160 of the second encapsulant 121 may be ananti-reflective thin film, so that the FWHM of the emitting light has aclear cut-off and the photodiode receive more signal light withoutunnecessary reflection. In the application of fluorescence detectionlong-pass filter thin film may be applied to the second encapsulant 121to acquire a clear fluorescent signal avoiding the excitation light.

The integration facilitates acquisition of the optical and electricalsignals and computation of acquired signals into meaningful information.The dual sensing device 18 is capable of acquiring optical andelectrical signals in situ and computing useful physiologicalparameters. First, the electric potential difference between twoelectrodes may be measured by parallel connection to the object circuit.For example, electrocardiogram may be acquired in time series bymeasuring the potential difference between the electrodes on the bodysurface with an adequate alignment. Also, the electric impedance of thecontact object may be measured by series connection to the objectsurface 190. For example, the fat content or hydration status of thebiological tissue may be further calculated from the measured impedance.In addition, the electrodes may also serve as a thermocouple to measurethe object temperature. For example, body surface temperature may bemeasured as a reference of core temperature. For example, the pulse wavevelocity can be calculated from the pulse phase difference, and somedisease status may be inferred from the phase angle of the bioelectricalimpedance.

In general, an optical sensing device or an optical sensing accessory isan integration of one or more optical sensor modules 10 with otherelectronic modules in a housing. Other electronic modules are configuredto assist the optical sensor module 10 in transmitting, digitizing,processing, or storing the optical signals and to combine the opticalsignals with other concomitant information; meanwhile, the housing keepsall the electronic modules from external damage and provides a humaninterface for mobile use. The integration facilitates acquisition of theoptical signals and transformation of the acquired optical signals intomeaningful information. Specifically, within the range of opticalwindow, incident light can travel in a depth of a biological tissue, andtherefore, the information underneath the surface of the biologicaltissue can be extracted by the reflected light. By studying the spectrumof specific wavelengths, people may further obtain the computedbiochemical or physiological parameters. The analysis of opticalproperties of a biological sample, in vivo, ex vivo, or in vitro, may beaccomplished through the operation of the optical sensing device.Accordingly, the acquired optical signals are more accessible andapplicable with the present technology of the optical sensing device.

With certain purposes of application, the optical sensing device or theoptical sensing accessory have, at least, an optical sensor module and ahousing. An optical sensor module may be the optical sensor module, themulti-directional optical sensor module, or the dual sensor moduledefined in the present disclosure. The other electronic modules may be amicroprocessor 20, a communication module 60, a battery 50, a memory 40,a GPS receiver module 70, or other types of sensors; a wearable housingis configured to carry an optical sensing device and attaching humanbody for mobile use.

A microprocessor 20 may be an ARM based or 8086x microprocessor, mostavailable in mobile device, are capable of processing the large amountof data and have an advantage of energy saving. A microprocessor 20 mayhave analogue input pins allowing analogue signal processing.

The input interface module 31 include keyboard, mouse, or microphone inconventional computing devices, or touch screen, microphone, or camerain mobile devices. The output interface module can output information invisual or audible forms. The visual output module 36 may be amicroprojector, LCD, LED, OLED, or E-Paper display, and the audibleoutput module 37 may be a beeper, a speaker, or a piezoelectric buzzer.

A memory 40 stores the digital information assigned by themicroprocessor 20 of the optical sensing device. The memory 40 may workas a system buffer to deal with abundant data input, and may work as astorage to preserve the structured information for later exporting tothe other computing device or a cloud server. The memory 40 may bevolatile or non-volatile. Volatile memory is embodied as random accessmemory (RAM) in most mobile device, and non-volatile memory is embodiedas flash memory.

A power supply provides the power necessitated for the operation of thedevice. A power supply may be a battery 50, a transformer, or a powertransmission line connected to a direct current source. Both primary andsecondary batteries may be a source of power supply used in the opticalsensing device. In at least one example, the primary and secondarybatteries can rely upon lithium battery technology. In other examples,the primary and secondary batteries can be made using technology toallow the desired discharge rates, life cycle, and rechargeablity.

A communication module 60 transmits the electrical signals between anoptical sensing device and an external device, where the electricalsignals may be control signals or data signals. The communication module60 may be wired 61 or wireless 66. Wired communication module 61 may bea serial port such as one wire, USB, I2C, or SPI. Wireless communicationmodule 66 may be Wi-Fi, standard Bluetooth, Bluetooth Low Energy, orcellular mobile network (for example, GSM, 3G, or 4G). In one example,an analogue front end is integrated as a part of Bluetooth module, whichenables the analogue signals to be transmitted.

A GPS receiver module 70 is configured to gather geographic information,and help to record the location where the optical information iscollected. With time series recording, the GPS information provides adynamic tracing of the user's displacement and velocity.

Other sensors transducing thermal, mechanical, or biopotential signalsinto electrical signals may be also incorporated into the opticalsensing device to provide more environmental and physiologicalinformation. For example, electrical thermometer 82 is able to detectthe ambient and body temperature; accelerometer 81 detects body motion;electrocardiograph leads detect cardiac electric activity. Besides, theelectrical property of biological tissue (for example, electricalimpedance, or conductivity) may indicate some physiological information(for example, body fat index, or moisture.)

A housing provides suitable container to set up the optical module andelectronic modules and may provide adequate connection interface forcommunication with external devices. It also helps measurementconsistency on specific body regions and increases the user complianceto the optical sensing device. A housing may be embodied as a housingfor a handheld device or a wearable device. A handheld housing 91features its compact size, light weight, and robustness for mobileapplications (FIG. 80A). A wearable housing comprises a body attachingpart and a module carrying part. The body attaching part may be anannular shape accessory 96, which attaches to human body by embracingbody parts, and may be embodied as, a wrist band (FIG. 80B), a headband, an ankle band, a necklace, a belt, a watch (FIG. 80C), or thelike. Also, the body attaching part may be a patch shape accessory 97,which attaches to human body by biocompatible glues or gels, and may beembodied as a tape, a pad (FIG. 80D), a patch, or the like. Furthermore,the body attaching part may be a hook shape, and may be embodied as anearplug, an on-ear accessory, or a spectacle frame. In one example asshown in FIG. 87D, the housing may comprise transparent opening 153 toprovide an optical path for the reflective optical sensor module, theoptical sensor module, the multi-directional optical sensor module 5, orthe dual sensor module. The transparent opening 153 may have a cover 150and the cover may be configured with microstructure, curvature lens, orthin film on the surfaces of the cover, or any combinations asmentioned.

In the present disclosure, an optical sensing accessory 11 or an opticalsensing device 12 may comprise an optical sensor module 10, amulti-directional optical sensor module 5, a dual sensor module 6, orany combinations. For ease of description, an optical sensing accessoryor an optical sensing device 12 comprising, but not limited to, anoptical sensor module 10 is demonstrated. An optical sensing accessory11 has a communication module 60 to allow the transmission of acquiredsignals to a computing device for further signal processing. An opticalsensing device 12 has a processor to manage the acquired opticalsignals. The embodiments of an optical sensing device are exemplified asbelow.

An optical sensing accessory 11 of the present disclosure is configuredto transmit the optical signals from one or more optical sensor modules10 to a computing device. The optical sensing accessory 11 comprises atleast one optical sensor module 10, a communication module 60, and ahousing. The optical signals are obtained by the optical sensor module10, and later, the signals may be conveyed to an independent computingdevice via the communication module 60 (FIG. 81A). The computing device9 may be the optical sensing device 12 or a mobile device (for example,smart phone). As depicted in FIGS. 81A-C, an optical sensing accessory11 to transmit the electrical signals to a computing device. In oneexample, the optical sensing accessory 11 comprises an optical sensormodule 10, a serial cable plug and a wearable housing presented as awired patch probe. With connection to an external computing device, theoptical sensing accessory receives power support and the control signalsfrom the computing device and delivers the converted signals to acomputing device via the serial cable (FIG. 81B). In addition, the wiredpatch probe may comprise multiple optical sensor modules 10 as shown inFIG. 81C. In the case of a wireless optical sensing accessory (FIG.82A), a battery 50 is necessary to power the signal transmission byradiofrequency. The computing device is capable of triggering theoperation of the optical sensing accessory 11 and managing the receivedsignals. As shown in FIG. 82B, multiple wireless optical sensingaccessories 11 may be connected and integrated to the computing device.

Also, an optical sensing device 12 of the present embodiments isconfigured to manage the optical signals from an internal optical sensormodule 10 or an external sensing devices 8. An internal optical sensormodule 10 is electrically connected to the microprocessor 20, while anexternal sensing device is connected through a communication module 60.The optical sensing device 12 comprises an optical sensor module 10, amicroprocessor 20, a battery 50, a memory 40, and a housing.

As depicted in FIGS. 83A-C, an optical sensing device 12 is configuredto receive, process, store and transmit the optical signals. In at leastone example, the optical sensing device 12 comprise an optical sensormodule 10, an ARM core microprocessor, a flash memory, and a lithiumbattery. The optical sensor module 10 may receive and convert theoptical signals of a biological tissue to electrical signals and deliverthe signals to a microprocessor 20. The general architecture of anoptical sensing device 12 is shown as FIG. 83A, and the other electronicmodules may be integrated into the optical sensing device 12. Theoptical signals are obtained by the optical sensor module 10. Later, theelectrical signals may be directly delivered to and processed by theoptical sensing device 12. The optical sensing device 12 comprisingelectronic modules is presented as an optical sensing watch 12 (FIGS.83B and 83C). The acquired optical signal is transduced into theelectrical signal and the electrical signal is processed by themicroprocessor 20, output as physiological parameters, and then storedin the memory. For example, the infrared and red light absorbance ofapplied biological tissue is detected by the optical sensor module 10,converted into electrical signals, processed as physiological parameters(for example, oxygen saturation), and stored in a flash memory. In FIG.83B, an optical sensing watch comprises one transparent opening 153 onthe clock face and one optical sensor module 10 is located in thetransparent opening. In FIG. 83C, the optical sensing watch comprisesthe other transparent opening 153 on the case back and the other opticalsensor module 10 is located in the transparent opening 153.

The optical sensing device 12 may comprise an optical sensor module 10,an ARM core microprocessor, a flash memory, a lithium battery, andfurther comprises an input module 31 a visual output module 36, and anaudible output module 37. The input interface module 31 may be embodiedas a touch screen module. The user may input a request by touch screento have the optical sensing device 12 send out control signal to thesensor module to acquire signals. The acquired signals are thenprocessed by the microprocessor 20 and stored as physiologicalinformation in the memory 40 in the optical sensing device 12. The usermay also input a request by touch screen to have the storedphysiological information be shown on a display. Additionally, an outputmodule, such as a beeper, may work as a failure-proof reminder or anemergency alerting signal.

With further comprising a communication module 60, the optical sensingdevice 12 is capable of integrating the information between the opticalsensing device 12 and other external devices. As shown in FIG. 83A, theoptical sensing device 12 comprises a microprocessor 20, a communicationmodule 60, a memory 40, and a battery 50. The communication module 60 isembodied as a Bluetooth module communicating with an external device.The optical sensing device 12 may send out control signal to control anexternal device or receive the signals acquired from an external device.For example, the external device may be an optical sensing accessory 11(FIG. 84A) so that the optical signals obtained from the optical sensingaccessory 11 may be integrated with other health information. Also, theexternal device may be other accessory sensor devices (FIG. 84B), sothat the optical sensing device 12 provides more compatibility forvarious applications.

The wearable optical sensing device 12 may also connect to the otheroptical sensing device 12 to deliver the physiological information forfurther information management. In at least one example, the othercomputing device may be a handheld optical sensing device 12 or a smartmobile device (for example, iPhone, Android phone, phablet, or tablets),so that the optical sensing device 12 may have lower power consumption,lower hardware requirement, and better compatibility.

In one example as shown in FIG. 85A, an optical sensing device 12connected to the other optical sensing device 12. One of the opticalsensing device has basic electronic modules, including an optical sensormodule 10, a microprocessor 20, and a wireless communication module 66,to connect with the other optical sensing device with more functionalelectronic modules. In FIG. 85B, one of the optical sensing device is awearable optical sensing watch and the other is an optical sensing smartphone.

Multi-site measurement is applicable since the wearable optical sensingdevice improves measurement accuracy and user compliance to record theirphysiological condition with the aid of the present technology. With theadvance performance of the reflective optical sensor module 10,measurement of multiple body regions brings extra useful physiologicalinformation. Here, blood oxygenation is illustrated to exploit theutility, while other optical signals from multiple body regions may havefurther applications. The physiological parameters from multiple bodyregions demonstrates the regional difference of a physiologicalparameter among the body parts. For example, the blood oxygenation mayvary from forehead and wrist. Also, the phase difference demonstratesthe conveyance of a physiological parameter between any two bodyregions. For example, the pulse wave velocity can be calculated from thepulse phase difference. In addition, continuous multiple body regionmonitoring may provide a temporal-anatomical distribution of thephysiological information. The example in FIGS. 86A and 86B shows theoptical sensing device 12. The optical sensing device 12 may be appliedto measure forehead and wrist (FIG. 86A), or a wrist and a finger of thecontralateral hand (FIG. 86B). Multiple optical measurements may also beacquired through the optical sensing accessory 11 with multiple probesas shown in FIG. 81C. In addition, the multiple optical measurements maybe achieved under the integration of multiple optical sensing accessory11.

In one example, the optical sensing device 12 comprises a bi-directionaloptical sensor module 5. The optical sensing device 12 may be a wearablewatch shown in FIG. 87A-D. In FIG. 87A, the housing of the opticalsensing device 12 have one opening on the internal side of the annularhousing, and in FIG. 87B, the other opening on the external side of theannular housing. The openings are configured to expose the contactsurfaces of the bi-directional optical sensor module 5, so that thelight emitted from the light source 110 may be collected by thephotodetectors 120 facing different directions. In FIG. 87C, theperspective view from the lateral side shows that the bi-directionalsensor module 5 have one contact surface facing toward the external sideof the housing and the other contact surface facing toward the internalside of the housing. In FIG. 87D, an enlarged view shows abi-directional sensor module 5 located in the wearable housing. Thebi-directional sensor module 5 is located in the transparent opening 153of the housing. The transparent opening 153 may further have a cover 150and the cover may be configured with microstructure, curvature lens, orthin film on the surfaces of the cover, or any combinations asmentioned.

The optical sensing device 12 may comprise an optical sensor module 10,an ARM core microprocessor, a flash memory, a lithium battery, andfurther comprises other sensor modules, or a GPS receiver module 70, sothe other associated information may be stored and processedconcomitantly with the physiological information. For example, bodytemperature may be acquired by an electrical thermometer 82, orelectrocardiogram (ECG) by ECG leads. The optical sensing device 12 maystore both blood oxygen saturation level and ECG information and furthercompute the pulse transit time (PTT) as blood pressure. Furthermore,motion information may be acquired by an accelerometer 81 to evaluatethe exercise status and applied for sport medicine. With the integratedGPS receiver module 70, the optical sensing device 12 can record theuser's physiological information including body temperature, ECG, bloodoxygenation, and blood pressure in a time series accompanying thecorrelated geographic location and exercise status. For example,geographic information obtained by a GPS receiver 70 may be stored withphysiological information for geo-medicine applications.

With the present technology, personal health information management maybring great benefits to the user in various applications. For example,the optical sensing device 12 may further comprises a communicationmodule 60 in order to connect to Internet and deliver the information toa cloud server to commit big data collection and analysis. Moreover, theoptical sensing device 12 may make an alert to the user or other peoplearound when the optical sensing device 12 sensing abnormal physiologicalconditions. In emergency situations, the optical sensing device 12 maymake a phone call or send out an instant message to inform a concernedauthority, such as a hospital or an emergency department, to ask animmediate action. By the present technology, the optical sensing device12 can realize the point of care (POC) service with comprehensiveinformation. Personal, portable, long-term, and continuous healthmonitoring can be achieved.

In general, a multi-site sensing device is the integration of multipleoptical sensor modules with other electronic modules in a housing. Otherelectronic modules are configured to assist the optical sensor modulesin transmitting, digitizing, processing, or storing the optical signalsand to combine the optical signals with other concomitant information;meanwhile, the housing keeps all the electronic modules from externaldamage and provides a human interface for mobile use. The integrationfacilitates acquisition of the optical signals and transformation of theacquired optical signals into meaningful information. Specifically,within the range of optical window, incident light can travel in a depthof a biological tissue, and therefore, the information underneath thesurface of the biological tissue can be extracted by the reflectedlight. By studying the spectrum of specific wavelengths, people mayfurther obtain the computed biochemical or physiological parameters. Theanalysis of optical properties of a biological sample, in vivo, ex vivo,or in vitro, may be accomplished through the operation of the multi-sitesensing device. Accordingly, the acquired optical signals are moreaccessible and applicable with the present technology of the multi-sitesensing device.

The multi-site measurement may be acquired by a multi-site sensingaccessory 15, a multi-site sensing device 16, or a multi-site sensingsystem 17. The optical sensing accessory 15, an optical sensing device16, or an optical sensing system 17 comprises at least two reflectiveoptical sensor modules 109. The reflective optical sensor module 109 isconfigured to emit light and to measure the reflected light from anobject surface. The reflective optical sensor module may be the opticalsensor module 10, the multi-directional optical sensor module 5, or thedual sensor module 6. The reflective optical sensor module 109 may alsobe a sensor module comprising at least the light source 110 and thephotodetector 120.

In the present disclosure, the example of a multi-site sensing accessory15, an multi-site sensing device 16, and a multi-site sensing system 17are illustrated in FIG. 88-90.

A multi-site sensing accessory 15 is configured to transmit the opticalsignals from multiple optical sensor modules to a computing device. Amulti-site sensing accessory 15 has a communication module 60 to allowthe transmission of acquired signals to a computing device for furthersignal processing. The multi-site sensing accessory 15 comprises pluralreflective optical sensor modules, a communication module 60, and ahousing. The optical signals are first transduced into electricalsignals by the reflective optical sensor modules. Later, the electricalsignals may be conveyed to an independent computing device via thecommunication module 60 (FIG. 88). The optical sensing accessory 15transmits the electrical signals from multiple reflective optical sensormodules to a computing device through the communication module 60. In atleast one example, the multi-site sensing accessory 15 comprises threereflective optical sensor modules, a serial cable plug and a wearablehousing presented as a wired patch probe. With connection to an externalcomputing device 9, the multi-site sensing accessory 15 receives powersupport and the control signals from the computing device and deliversthe converted signals to a computing device via the serial cable. In thecase of a wireless communication module 66, a battery 50 is necessary topower the signal transmission by radiofrequency. The coupling externalcomputing device is capable of triggering the operation of themulti-site sensing accessory 15 and managing the received opticalsignals. The multi-site sensing accessory 15 may have a small volume andbe suitable for mobile applications. Most collected physiologicalinformation is then transmitted to a mobile device and is furtherprocessed.

Also, a multi-site sensing device 16 of the present disclosure isconfigured to manage the optical signals from an internal reflectiveoptical sensor module or an external sensing devices. At least tworeflective optical sensor modules 109 are electronically connected tothe microprocessor 20, while an external sensing device is connectedthrough a communication module 60. The multi-site sensing device 16comprises at least two reflective optical sensor modules 109, amicroprocessor 20, a battery 50, a memory 40, and a housing. The generalarchitecture is shown as FIG. 89, and the other electronic modules maybe integrated into the multi-site sensing device 16. The optical signalsare obtained by the optical sensor modules. Later, the electricalsignals may be directly delivered to and processed by the microprocessor20.

The optical sensor module may receive and convert the optical signals ofa biological tissue to electrical signals and deliver the signals to amicroprocessor 20. The multi-site sensing device 16 comprisingelectronic modules is presented as a multi-site sensing watch (FIGS.87A-87D). The acquired optical signals are processed by themicroprocessor 20, output as physiological parameters, and then storedin the memory 40. For example, the infrared and red light absorbance ofapplied biological tissue is detected by the optical sensor modules,converted into electrical signals, processed as physiological parameters(for example, oxygen saturation), and stored in a flash memory.

In FIG. 90, the multi-site sensing system 17 may comprise an opticalsensing accessory and an optical sensing device. The optical sensoraccessory comprises a first reflective optical sensor module 109, afirst communication module 60 and a first housing, and the opticalsensing device comprises a second reflective optical sensor module 109,a microprocessor 20, a battery 50, a memory 40, a second communicationmodule 60 and a second housing. The communication module 60 may be awireless communication module 66 which is, for example, a Bluetoothmodule communicating within the optical sensing system 17. The opticalsensing device may send out control signal to control or receive thesignals acquired from the optical sensing accessory.

Multi-site measurement is applicable since the multi-site sensing deviceimproves measurement accuracy and user compliance to record theirphysiological condition with the aid of the present technology. With theadvance performance of the multi-site sensing device, measurement ofmultiple body regions brings extra useful physiological information.Here, blood oxygenation is illustrated to exploit the utility, whileother optical signals from multiple body regions may have furtherapplications. First, the physiological parameters from multiple bodyregions demonstrates the regional difference of a physiologicalparameter among the body parts. For example, the blood oxygenation mayvary from forehead and wrist. Second, the phase difference demonstratesthe conveyance of a physiological parameter between any two bodyregions. For example, the pulse wave velocity can be calculated from thepulse phase difference. Third, continuous multiple body regionmonitoring may provide a temporal-anatomical distribution of thephysiological information.

The reflective optical sensor module is used for the measurement ofoverall optical reflectance of an object surface. The acquired opticalsignals may be computed as useful information, especially physiologicalinformation, such as the blood oxygen saturation level, which is basedon the light absorption rate of particular wavelengths. Furtherphysiological information may be derived from the acquired opticalinformation at multiple parts of human body. For example, the bloodoxygen saturation levels may be compared between contralateral sides ofextremities, which may indicate regional hypoxia, between upper andlower extremities, for example, the Ankle Brachial Pressure Indexindicating the condition of peripheral arteries, or between any twodistinct parts of human body.

The embodiments shown and described above are only examples. Manydetails are often found in the art such as the other features.Therefore, many such details are neither shown nor described. Eventhough numerous characteristics and advantages of the present technologyhave been set forth in the foregoing description, together with detailsof the structure and function of the present disclosure, the disclosureis illustrative only, and changes may be made in the detail, includingin matters of shape and arrangement of the parts within the principlesof the present disclosure up to, and including the full extentestablished by the broad general meaning of the terms used in theclaims. It will therefore be appreciated that the embodiments describedabove may be modified within the scope of the claims.

What is claimed is:
 1. An optical sensor module comprising: a substrate;a light source disposed on the substrate; a first encapsulant formedover the light source; a photodetector disposed on the substrate; asecond encapsulant formed over the photodetector; a partition coupled tothe substrate and located between the light source and thephotodetector; and a microstructure formed on an outer profile of atleast one of the first encapsulant and the second encapsulant; whereineach of the first encapsulant and the second encapsulant has a topsurface and a medial surface, the medial surface is between thesubstrate and the top surface and is substantially facing the partition,and the partition is spaced apart from the medial surface of the atleast one of the first encapsulant and the second encapsulant by apredetermined distance.
 2. The optical sensor module of claim 1, furthercomprising an optical directional component on the medial surface of theat least one of the first and the second encapsulants.
 3. The opticalsensor module of claim 2, wherein the optical directional component isconfigured as an inclined plane.
 4. The optical sensor module of claim2, wherein the optical directional component is configured as acurvature lens.
 5. The optical sensor module of claim 1, wherein thephotodetector is substantially annularly arranged around the lightsource.
 6. The optical sensor module of claim 1, wherein the secondencapsulant is substantially annularly arranged around the light source.7. The optical sensor module of claim 1, further comprising a packagingwall and a cover, wherein the packaging wall is coupled to the substrateand defines an area surrounding the light source, the partition, and thephotodetector; the cover is disposed on the packaging wall and isconfigured for passing light through and keeping optical path clear. 8.The optical sensor module of claim 1, further comprising a cover,wherein the cover is arranged above both the first encapsulant and thesecond encapsulant, and the cover is configured for passing lightthrough and keeping optical path clear.
 9. The optical sensor module ofclaim 8, wherein a surface of the cover comprises a curvature lens. 10.The optical sensor module of claim 8, wherein a surface of the covercomprises a microstructure.
 11. The optical sensor module of claim 8,wherein an internal surface of the cover is coated with a thin film, thethin film is selected from a group consisting of an anti-scratch thinfilm, an anti-reflective thin film, and a filter thin film.
 12. Theoptical sensor module of claim 1, wherein the optical sensor modulefurther comprises at least one of an analogue front end, amicrocontroller, an operational amplifier, and a light source driver.13. An optical sensing accessory comprising: at least one optical sensormodule of claim 1; a communication module electrically connected to theoptical sensor module; and a housing containing the at least one opticalsensor module and the communication module.
 14. An optical sensingdevice comprising: at least one optical sensor module of claim 1; amicroprocessor electrically connected to the optical sensor module; amemory electrically connected to the optical sensor module and themicroprocessor; a power supply electrically connected to the opticalsensor module and the memory; and a housing containing the at least oneoptical sensor module, the microprocessor, the memory and the powersupply.
 15. The optical sensor module of claim 8, wherein an externalsurface of the cover is coated with a thin film, the thin film isselected from a group consisting of an anti-scratch thin film, ananti-reflective thin film, and a filter thin film.
 16. The opticalsensor module of claim 8, wherein an internal surface of the cover isspaced apart from the top surfaces of the first encapsulant and thesecond encapsulant by a predetermined distance.
 17. The optical sensormodule of claim 1, wherein the microstructure is a refractivemicrostructure or a diffractive microstructure, and the microstructureis configured for concentrating light toward a predetermined direction.18. The optical sensor module of claim 17, wherein the refractivemicrostructure is configured as a Fresnel lens microstructure.
 19. Theoptical sensor module of claim 17, wherein the diffractivemicrostructure is configured as a diffractive optical elementmicrostructure.
 20. The optical sensor module of claim 1, wherein themicrostructure is configured as a concentric circular pattern.
 21. Theoptical sensor module of claim 1, wherein the microstructure isconfigured as a set of concentric arcs concave toward the photodetector.22. The optical sensor module of claim 1, wherein the partition isformed by an opaque material and is configured to a predetermined heightto prevent light emitted from the light source directly to thephotodetector.